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.util.*;
  import java.lang.*;
  import java.io.*;
  import java.util.stream.Collectors;
  
  
  public class cf {
      static PrintWriter out;
      static int MOD = 1000000007;
      static FastReader scan;
  
      /*-------- I/O using short named function ---------*/
      public static String ns() {
          return scan.next();
      }
  
      public static int ni() {
          return scan.nextInt();
      }
  
      public static long nl() {
          return scan.nextLong();
      }
  
      public static double nd() {
          return scan.nextDouble();
      }
  
      public static String nln() {
          return scan.nextLine();
      }
  
      public static void p(Object o) {
          out.print(o);
      }
  
      public static void ps(Object o) {
          out.print(o + " ");
      }
  
      public static void pn(Object o) {
          out.println(o);
      }
  
      /*-------- for output of an array ---------------------*/
      static void iPA(int arr[]) {
          StringBuilder output = new StringBuilder();
          for (int i = 0; i < arr.length; i++) output.append(arr[i] + " ");
          out.println(output);
      }
  
      static void lPA(long arr[]) {
          StringBuilder output = new StringBuilder();
          for (int i = 0; i < arr.length; i++) output.append(arr[i] + " ");
          out.println(output);
      }
  
      static void sPA(String arr[]) {
          StringBuilder output = new StringBuilder();
          for (int i = 0; i < arr.length; i++) output.append(arr[i] + " ");
          out.println(output);
      }
  
      static void dPA(double arr[]) {
          StringBuilder output = new StringBuilder();
          for (int i = 0; i < arr.length; i++) output.append(arr[i] + " ");
          out.println(output);
      }
  
      /*-------------- for input in an array ---------------------*/
      static void iIA(int arr[]) {
          for (int i = 0; i < arr.length; i++) arr[i] = ni();
      }
  
      static void lIA(long arr[]) {
          for (int i = 0; i < arr.length; i++) arr[i] = nl();
      }
  
      static void sIA(String arr[]) {
          for (int i = 0; i < arr.length; i++) arr[i] = ns();
      }
  
      static void dIA(double arr[]) {
          for (int i = 0; i < arr.length; i++) arr[i] = nd();
      }
  
      /*------------ for taking input faster ----------------*/
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader() {
              br = new BufferedReader(new InputStreamReader(System.in));
          }
  
          String next() {
              while (st == null || !st.hasMoreElements()) {
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
  
          String nextLine() {
              String str = "";
              try {
                  str = br.readLine();
              } catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
      }
  
      public static ArrayList<Integer> sieveOfEratosthenes(int n) {
          // Create a boolean array
          // "prime[0..n]" and
          // initialize all entries
          // it as true. A value in
          // prime[i] will finally be
          // false if i is Not a
          // prime, else true.
          boolean prime[] = new boolean[n + 1];
          for (int i = 0; i <= n; i++)
              prime[i] = true;
  
          for (int p = 2; p * p <= n; p++) {
              // If prime[p] is not changed, then it is a
              // prime
              if (prime[p] == true) {
                  // Update all multiples of p
                  for (int i = p * p; i <= n; i += p)
                      prime[i] = false;
              }
          }
          ArrayList<Integer> arr = new ArrayList<>();
          // Print all prime numbers
          for (int i = 2; i <= n; i++) {
              if (prime[i] == true)
                  arr.add(i);
          }
          return arr;
      }
  
      // Method to check if x is power of 2
      static boolean isPowerOfTwo(int x) {
          return x != 0 && ((x & (x - 1)) == 0);
      }
  
      //Method to return lcm of two numbers
      static int gcd(int a, int b) {
          return a == 0 ? b : gcd(b % a, a);
      }
  
      //Method to count digit of a number
      static int countDigit(long n) {
          String sex = Long.toString(n);
          return sex.length();
      }
  
      static void reverse(int a[]) {
          int i, k, t;
          int n = a.length;
          for (i = 0; i < n / 2; i++) {
              t = a[i];
              a[i] = a[n - i - 1];
              a[n - i - 1] = t;
          }
      }
  
      static final Random random = new Random();
  
      //Method for sorting
      static void ruffleSort(int[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = random.nextInt(n);
              int temp = arr[j];
              arr[j] = arr[i];
              arr[i] = temp;
          }
          Arrays.sort(arr);
      }
  
      static void sortadv(long[] a) {
          ArrayList<Long> l = new ArrayList<>();
          for (long value : a) {
              l.add(value);
          }
          Collections.sort(l);
          for (int i = 0; i < l.size(); i++)
              a[i] = l.get(i);
      }
  
      //Method for checking if a number is prime or not
      static boolean isPrime(int n) {
          if (n <= 1) return false;
          if (n <= 3) return true;
          if (n % 2 == 0 || n % 3 == 0) return false;
          for (int i = 5; i * i <= n; i = i + 6)
              if (n % i == 0 || n % (i + 2) == 0)
                  return false;
          return true;
      }
  
      public static void main(String[] args) throws java.lang.Exception {
          OutputStream outputStream = System.out;
          out = new PrintWriter(outputStream);
          scan = new FastReader();
          //for fast output sometimes
          StringBuilder sb = new StringBuilder();
          int t = ni();
  
          while (t-- != 0) {
              int n=ni();
              char c=ns().charAt(0);
              char[] ch=ns().toCharArray();
              boolean odd=false;
              boolean even=false;
              for(int i=0;i<n;i++){
                  if(ch[i]!=c){
                      if(i%2==0)
                          even=true;
                      else
                          odd=true;
                  }
              }
              if(!odd&&!even)
                  pn(0);
  
              else{// both true
                  if(ch[n-1]==c){
                      pn(1);
                      pn(n);
                  }
                  else if(ch[n-2]==c){
                      pn(1);
                      pn(n-1);
                  }
                  else{
                      int temp=-1;
                      for(int i=n/2 ;i<n;i++){
                          if(ch[i]==c)
                          {
                              temp=i+1;
                          }
                      }
                      if(temp!=-1){
                          pn(1);
                          pn(temp);
                      }
                      else {
                          pn(2);
                          pn((n - 1) + " " + (n));
                      }
                  }
              }
          }
          out.flush();
          out.close();
      }
      public static boolean equa(int[] a,int[] b,int n){
          for(int i=0;i<n;i++){
              if(a[i]!=b[i])
                  return false;
          }
          return true;
      }
      public static void rightRotate(int arr[], int d, int n)
      {
          // if arr is rotated n times then
          // you get the same array
          while (d > n) {
              d = d - n;
          }
  
          // create temp array of size d
          int temp[] = new int[n - d];
  
          // copy first N-D element in array temp
          for (int i = 0; i < n - d; i++)
              temp[i] = arr[i];
  
          // move the rest element to index
          // zero to D
          for (int i = n - d; i < n; i++) {
              arr[i - n + d] = arr[i];
          }
  
          // copy the temp array element
          // in origninal array
          for (int i = 0; i < n - d; i++) {
              arr[i + d] = temp[i];
          }
      }
      public static class Node{
          int val;Node next;
          Node(int v){
              val=v;
              next=null;
          }
      }
      public static class Pair{
          int first;int second;
          Pair(int f,int s){
              first=f;
              second=s;
          }
      }
  }
  
  
  
  
  