description: Theofanis has a string s_1 s_2 ... s_n and a character c. He wants to make all characters of the string equal to c using the minimum number of operations.
  
  In one operation he can choose a number x (1 ≤ x ≤ n) and for every position i, where i is not divisible by x, replace s_i with c. 
  
  Find the minimum number of operations required to make all the characters equal to c and the x-s that he should use in his operations.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.
  
  The first line of each test case contains the integer n (3 ≤ n ≤ 3 ⋅ 10^5) and a lowercase Latin letter c — the length of the string s and the character the resulting string should consist of.
  
  The second line of each test case contains a string s of lowercase Latin letters — the initial string.
  
  It is guaranteed that the sum of n over all test cases does not exceed 3 ⋅ 10^5.
  
  Output
  
  For each test case, firstly print one integer m — the minimum number of operations required to make all the characters equal to c.
  
  Next, print m integers x_1, x_2, ..., x_m (1 ≤ x_j ≤ n) — the x-s that should be used in the order they are given.
  
  It can be proved that under given constraints, an answer always exists. If there are multiple answers, print any.
  
  Example
  
  Input
  
  
  3
  4 a
  aaaa
  4 a
  baaa
  4 b
  bzyx
  
  
  Output
  
  
  0
  1
  2
  2 
  2 3
  
  Note
  
  Let's describe what happens in the third test case: 
  
    1. x_1 = 2: we choose all positions that are not divisible by 2 and replace them, i. e. bzyx → bzbx; 
    2. x_2 = 3: we choose all positions that are not divisible by 3 and replace them, i. e. bzbx → bbbb. 
solution:     import java.io.BufferedReader;
      import java.io.FileInputStream;
      import java.io.FileNotFoundException;
      import java.io.IOException;
      import java.io.InputStreamReader;
      import java.util.*;
      import java.util.concurrent.LinkedBlockingDeque;
  
      import javax.print.attribute.HashAttributeSet;
      import javax.swing.JLabel;
  
      import java.io.PrintStream;
                  
                      public class Solution {
  
                          public static boolean Local(){
                              try{ 
                                  return System.getenv("LOCAL_SYS")!=null;
                              }catch(Exception e){
                                  return false;
                              }
                          }   
  
                          public static boolean LOCAL;
  
                          static class FastScanner {
  
                                  BufferedReader br;
                                  StringTokenizer st ;
  
                                  FastScanner(){
                                      br =  new BufferedReader(new InputStreamReader(System.in));
                                      st = new StringTokenizer("");
                                  }
  
                                  FastScanner(String file) {
  
                                      try{
                                          br =  new BufferedReader(new InputStreamReader(new FileInputStream(file)));
                                          st = new StringTokenizer("");
                                      }catch(FileNotFoundException e) {
                                          // TODO Auto-generated catch block
                                          System.out.println("file not found");
                                          e.printStackTrace();
                                      }
                                      
                                  }
                                  
  
                                  String next() {
                                      while (!st.hasMoreTokens())
                                          try {
                                              st = new StringTokenizer(br.readLine());
                                          } catch (IOException e) {
                                          }
                                      return st.nextToken();
                                  }
  
                                  int nextInt() {
                                      return Integer.parseInt(next());
                                  }
  
                                  long nextLong() {
                                      return Long.parseLong(next());
                                  }
                                  String readLine() throws IOException{
                                      return br.readLine();
                                  }
                              }
                                                  
                          static class Pair<T,X> {
  
                              T first;
                              X second;
                              
                              Pair(T first,X second){
                                  this.first = first;
                                  this.second = second;
                              }
  
                              @Override
                              public int hashCode(){
                                  return Objects.hash(first,second);
                              }
  
                              @Override
                              public boolean equals(Object obj){
                                  return obj.hashCode() == this.hashCode();
                              }
  
                          }
  
                      
                      static PrintStream debug = null;
  
                      static long mod = (long)(Math.pow(10,9) + 7); 
                      
  
                      public static void main(String[] args) throws Exception {
                          
                          FastScanner s = new FastScanner();
  
                          LOCAL = Local();
  
                          
                          if(LOCAL){
                              s = new FastScanner("src/input.txt");
                              PrintStream o = new PrintStream("src/sampleout.txt");
                              debug = new PrintStream("src/debug.txt");
                              System.setOut(o);
                          }
  
                          long mod = 1000000007;
                          int tcr =  s.nextInt();     
                      
                          StringBuilder sb = new StringBuilder();
  
                       
                      
                          for(int tc=0;tc<tcr;tc++){
                              int n = s.nextInt();
                            
                              char c = s.next().charAt(0);
                            
                              String str = s.next();
                            
                              List<Integer> pos = new ArrayList<>();
                            
                              for(int i=0;i<n;i++){
                                  
                                  if(Character.compare(str.charAt(i),c) != 0){
                                      pos.add((i+1));
                                  }
  
                              }
  
                              // dbg(debug,pos);
                              // dbg(debug,c);
                              
                              int cnt = 0;
                              List<Integer> x = new ArrayList<>();
                              if(pos.size() == 0){
                                  sb.append("0\n");
                                  continue;
                              }else{
                                  boolean all_odd = true;
                                  for(int i=0;i<pos.size();i++){
                                      if((pos.get(i) % 2) == 0){
                                          all_odd = false;break;
                                      }
                                  }
  
                                  if(all_odd){
                                   
                                      sb.append("1\n");
                                      sb.append("2\n");
                                      continue;
  
                                  }
  
                                  Pair<Boolean,Integer> temp = checkfor1(str,n,c);
  
                                  if(temp.first){
                                      sb.append(1+"\n");
                                      sb.append(temp.second+"\n");
                                      continue;
                                  }else{
                                      sb.append(2+"\n");
                                      sb.append((n-1)+" "+n+"\n");
                                  }
                              }
  
                          }
  
  
                          print(sb.toString());
                      }
  
                      public static Pair<Boolean,Integer> checkfor1(String str,int n,char c){
                         
                          for(int i=1;i<=n;i++){
                              int curr = i;
                              boolean poss = true;
                              while(curr <= n && (str.charAt(curr-1) == c)){
                                  curr+=i;
                              }
                             // if(i==4){println(curr);}
                              if(curr >= (n+1)){return new Pair<Boolean,Integer>(true,i);}
                         }
                         return new Pair<Boolean,Integer>(false,-1);
                      }
  
                      public static long ncr(int n,int r,long fact[]){
                          if(r==0){return 1l;}
                          long ans = fact[n];
                          long denom = mulmod(fact[r], fact[n-r], mod);
                          ans = mulmod(ans,modpow(denom,mod-2, mod),mod);
                          return ans;
                      }
  
                      public static List<long[]> prime_factors(long n){
                  
                          List<long[]> list = new ArrayList<>();
                          
                          for(long i=2;i<=(Math.sqrt(n));i++){
                  
                              if(n % i == 0){
                                  
                                  int cnt = 0;
                                  
                                  while( (n % i) == 0){
                                      n = n/i;
                                      cnt++;
                                      
                                  }
                  
                                  list.add(new long[]{i,cnt});
                              }
                          }
  
                  
                          if(n!=1){
                              list.add(new long[]{n,1l});
                          }
                  
                          return list;
                  
                      }
  
                      public static boolean check(int arr[]){
                          for(int i=1;i<arr.length;i++){
                              if(arr[i] < arr[i-1]){
                                  return false;
                              }
                          }
                          return true;
                      }
  
                  
                      public static boolean inRange(int r1,int r2,int val){
                          return ((val >= r1) && (val <= r2));
                      }
  
                      static int len(long num){
                          return Long.toString(num).length();
                      }
  
                      static long mulmod(long a, long b,long mod)
                      {
  
                          return (a*b)%mod;
                          
                          // long ans = 0l;
                          
                          // while(b > 0l){
                          //     long curr = (b & 1l);
                          //     if(curr == 1l){
                          //         ans = ((ans % mod) + a) % mod;
                          //     }
                              
                          //     a = (a + a) % mod;
  
                          //     b = b >> 1;
                          // }
  
                          // return ans;
                      }
  
  
                      public static void dbg(PrintStream ps,Object... o) throws Exception{
                          if(ps == null){
                              return;
                          }
                          Debug.dbg(ps,o);
                      }
  
                      public static long modpow(long num,long pow,long mod){
  
                          long val = num;
                          long ans = 1l;
  
                          while(pow > 0l){
                              
                              long bit = pow & 1l;
  
                              if(bit == 1){
                                  ans = (ans * (val%mod))%mod;
                              }
  
                              val = (val * val) % mod;
                              pow = pow >> 1;
                          }
  
                          return ans;
  
                      }
  
                      public static char get(int n){
                          return (char)('a' + n);
                      }
  
                      public static long[] sort(long arr[]){
                          List<Long> list = new ArrayList<>();
                          for(long n : arr){list.add(n);}
                          Collections.sort(list);
                          for(int i=0;i<arr.length;i++){
                              arr[i] = list.get(i);
                          }
                          return arr;
                      }
  
                      public static int[] sort(int arr[]){
                          List<Integer> list = new ArrayList<>();
                          for(int n : arr){list.add(n);}
                          Collections.sort(list);
                          for(int i=0;i<arr.length;i++){
                              arr[i] = list.get(i);
                          }
                          return arr;
                      }
  
                      // return the (index + 1)
                      // where index is the pos of just smaller element
                      // i.e count of elemets strictly less than num
                      public static int justSmaller(long arr[],long num){
                          //  System.out.println(num+"@");
                          int st = 0;
                          int e = arr.length - 1;
                  
                          int ans = -1;
                  
                          while(st <= e){
                  
                              int mid = (st + e)/2;
                  
                              if(arr[mid] >= num){
                                  e = mid - 1;
                              }else{
                                  ans = mid;
                                  st = mid + 1;
                              }
                  
                          }
                  
                  
                          return ans + 1;
                  
                      }
                      public static int justSmaller(int arr[],int num){
                          //  System.out.println(num+"@");
                          int st = 0;
                          int e = arr.length - 1;
                  
                          int ans = -1;
                  
                          while(st <= e){
                  
                              int mid = (st + e)/2;
                  
                              if(arr[mid] >= num){
                                  e = mid - 1;
                              }else{
                                  ans = mid;
                                  st = mid + 1;
                              }
                  
                          }
                  
                  
                          return ans + 1;
                  
                      }
                      
                      //return (index of just greater element)
                      //count of elements smaller than or equal to num
  
                      public static int justGreater(long arr[],long num){
                          int st = 0;
                          int e = arr.length - 1;
                  
                          int ans = arr.length;
                  
                          while(st <= e){
                              
                              int mid = (st + e)/2;
                  
                              if(arr[mid] <= num){
                                  st = mid + 1;
                              }else{
                                  ans = mid;
                                  e = mid - 1;
                              }
                          }
                  
                          return ans;
                  
                      }
  
                      public static int justGreater(int arr[],int num){
                          int st = 0;
                          int e = arr.length - 1;
                  
                          int ans = arr.length;
                  
                          while(st <= e){
                              
                              int mid = (st + e)/2;
                  
                              if(arr[mid] <= num){
                                  st = mid + 1;
                              }else{
                                  ans = mid;
                                  e = mid - 1;
                              }
                          }
                  
                          return ans;
                  
                      }
                  
                      
  
                      public static void println(Object obj){
                          System.out.println(obj.toString());
                      }
  
                      public static void print(Object obj){
                          System.out.print(obj.toString());
                      }
  
                      public static int gcd(int a,int b){
                          if(b == 0){return a;}
                          return gcd(b,a%b);
                      }
  
                      public static long gcd(long a,long b){
                          if(b == 0l){
                              return a;
                          }
  
                          return gcd(b,a%b);
                      }
  
                      public static int find(int parent[],int v){
                          if(parent[v] == v){
                              return v;
                          }
                          
                          return parent[v] = find(parent, parent[v]);
                      }
  
                  
  
                      public static List<Integer> sieve(){
                      
                              List<Integer> prime = new ArrayList<>();
  
                              int arr[] = new int[300001];
  
                          Arrays.fill(arr,1);
  
                          arr[1] = 0;
                          arr[2] = 1;
  
                          for(int i=2;i<300001;i++){
                              
                              if(arr[i] == 1){
                                  
                                  prime.add(i);
  
                                  for(long j = (i*1l*i);j<300001;j+=i){
                                      arr[(int)j] = 0;
                                  }
                              }
                          }
  
                          return prime;
                      }
  
                      static boolean isPower(long n,long a){
                          
                          long log = (long)(Math.log(n)/Math.log(a));
  
                          long power = (long)Math.pow(a,log);
  
                          if(power == n){return true;}
  
                          return false;
                      }
  
  
                      private static int mergeAndCount(int[] arr, int l,int m, int r)
                      {
  
                          // Left subarray
                          int[] left =  Arrays.copyOfRange(arr, l, m + 1);
  
                          // Right subarray
                          int[] right = Arrays.copyOfRange(arr, m + 1, r + 1);
  
                          int i = 0, j = 0, k = l, swaps = 0;
  
                          while (i < left.length && j < right.length) {
                              if (left[i] <= right[j])
                                  arr[k++] = left[i++];
                              else {
                                  arr[k++] = right[j++];
                                  swaps += (m + 1) - (l + i);
                              }
                          }
                          while (i < left.length)
                              arr[k++] = left[i++];
                          while (j < right.length)
                              arr[k++] = right[j++];
                          return swaps;
                      }
  
                      // Merge sort function
                      private static int mergeSortAndCount(int[] arr, int l,int r)
                      {
  
                          // Keeps track of the inversion count at a
                          // particular node of the recursion tree
                          int count = 0;
  
                          if (l < r) {
                              int m = (l + r) / 2;
  
                              // Total inversion count = left subarray count
                              // + right subarray count + merge count
  
                              // Left subarray count
                              count += mergeSortAndCount(arr, l, m);
  
                              // Right subarray count
                              count += mergeSortAndCount(arr, m + 1, r);
  
                              // Merge count
                              count += mergeAndCount(arr, l, m, r);
                          }
  
                          return count;
                      }
  
                      static class Debug{
                          //change to System.getProperty("ONLINE_JUDGE")==null; for CodeForces
                          public static final boolean LOCAL = System.getProperty("ONLINE_JUDGE")==null;
  
                          
  
                          private static <T> String ts(T t) {
                              if(t==null) {
                                  return "null";
                              }
                              try {
                                  return ts((Iterable) t);
                              }catch(ClassCastException e) {
                                  if(t instanceof int[]) {
                                      String s = Arrays.toString((int[]) t);
                                      return "{"+s.substring(1, s.length()-1)+"}\n";
                                  }else if(t instanceof long[]) {
                                      String s = Arrays.toString((long[]) t);
                                      return "{"+s.substring(1, s.length()-1)+"}\n";
                                  }else if(t instanceof char[]) {
                                      String s = Arrays.toString((char[]) t);
                                      return "{"+s.substring(1, s.length()-1)+"}\n";
                                  }else if(t instanceof double[]) {
                                      String s = Arrays.toString((double[]) t);
                                      return "{"+s.substring(1, s.length()-1)+"}\n";
                                  }else if(t instanceof boolean[]) {
                                      String s = Arrays.toString((boolean[]) t);
                                      return "{"+s.substring(1, s.length()-1)+"}\n";
                                  }
                                  try {
                                      return ts((Object[]) t);
                                  }catch(ClassCastException e1) {
                                      return t.toString();
                                  }
                              }
                          }
                          private static <T> String ts(T[] arr) {
                              StringBuilder ret = new StringBuilder();
                              ret.append("{");
                              boolean first = true;
                              for(T t: arr) {
                                  if(!first) {
                                      ret.append(", ");
                                  }
                                  first = false;
                                  ret.append(ts(t));
                              }
                              ret.append("}");
                              return ret.toString();
                          }
                          private static <T> String ts(Iterable<T> iter) {
                              StringBuilder ret = new StringBuilder();
                              ret.append("{");
                              boolean first = true;
                              for(T t: iter) {
                                  if(!first) {
                                      ret.append(", ");
                                  }
                                  first = false;
                                  ret.append(ts(t));
                              }
                              ret.append("}");
                              return ret.toString();
                          }
                          public static void dbg(PrintStream ps,Object... o) throws Exception {
                              if(LOCAL) {
                                  System.setErr(ps);
                                  System.err.print("Line #"+Thread.currentThread().getStackTrace()[2].getLineNumber()+": [");
                                  for(int i = 0; i<o.length; i++) {
                                      if(i!=0) {
                                          System.err.print(", ");
                                      }
                                      System.err.print(ts(o[i]));
                                  }
                                  System.err.println("]");
                              }
                          }
                      }
  
              }
  
  
              