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.io.*;
  import java.math.*;
  
  public class three {
      static StringBuilder sb;
      static dsu dsu;
      static long fact[];
      static int mod = (int) (1e9 + 7);
  
      static void solve() {
          int n=i();
          char c=s().charAt(0);
          String str=s();
  
          int count=0;
          int last=-1;
          for(int i=0;i<n;i++){
              if(str.charAt(i)!=c){
                  count++;
              }else{
                  last=i;
              }
          }
          if(count==0){
              sb.append(0+"\n");
          }else if(last+1>n/2){
              sb.append(1+"\n"+(last+1)+"\n");
          }else{
              sb.append(2+"\n"+(n-1)+" "+n+"\n");
          }
  
      }
  
      public static void main(String[] args) {
          sb = new StringBuilder();
          int test = i();
          while (test-- > 0) {
              solve();
          }
          System.out.println(sb);
      }
  
      /*
       * fact=new long[(int)1e6+10]; fact[0]=fact[1]=1; for(int i=2;i<fact.length;i++)
       * { fact[i]=((long)(i%mod)1L(long)(fact[i-1]%mod))%mod; }
       */
      // **************NCR%P******************
      static long ncr(int n, int r) {
          if (r > n)
              return (long) 0;
  
          long res = fact[n] % mod;
          // System.out.println(res);
          res = ((long) (res % mod) * (long) (p(fact[r], mod - 2) % mod)) % mod;
          res = ((long) (res % mod) * (long) (p(fact[n - r], mod - 2) % mod)) % mod;
          // System.out.println(res);
          return res;
  
      }
  
      static long p(long x, long y)// POWER FXN //
      {
          if (y == 0)
              return 1;
  
          long res = 1;
          while (y > 0) {
              if (y % 2 == 1) {
                  res = (res * x) % mod;
                  y--;
              }
  
              x = (x * x) % mod;
              y = y / 2;
  
          }
          return res;
      }
  
      // **************END******************
  
      // *************Disjoint set
      // union*********//
      static class dsu {
          int parent[];
  
          dsu(int n) {
              parent = new int[n];
              for (int i = 0; i < n; i++)
                  parent[i] = -1;
          }
  
          int find(int a) {
              if (parent[a] < 0)
                  return a;
              else {
                  int x = find(parent[a]);
                  parent[a] = x;
                  return x;
              }
          }
  
          void merge(int a, int b) {
              a = find(a);
              b = find(b);
              if (a == b)
                  return;
              parent[b] = a;
          }
      }
  
      // **************PRIME FACTORIZE **********************************//
      static TreeMap<Integer, Integer> prime(long n) {
          TreeMap<Integer, Integer> h = new TreeMap<>();
          long num = n;
          for (int i = 2; i <= Math.sqrt(num); i++) {
              if (n % i == 0) {
                  int nt = 0;
                  while (n % i == 0) {
                      n = n / i;
                      nt++;
                  }
                  h.put(i, nt);
              }
          }
          if (n != 1)
              h.put((int) n, 1);
          return h;
  
      }
  
      // ****CLASS PAIR ************************************************
      static class Pair implements Comparable<Pair> {
          int x;
          long y;
  
          Pair(int x, long y) {
              this.x = x;
              this.y = y;
          }
  
          public int compareTo(Pair o) {
              return (int) (this.y - o.y);
  
          }
  
      }
      // ****CLASS PAIR **************************************************
  
      static class InputReader {
          private InputStream stream;
          private byte[] buf = new byte[1024];
          private int curChar;
          private int numChars;
          private SpaceCharFilter filter;
  
          public InputReader(InputStream stream) {
              this.stream = stream;
          }
  
          public int read() {
              if (numChars == -1)
                  throw new InputMismatchException();
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = stream.read(buf);
                  } catch (IOException e) {
                      throw new InputMismatchException();
                  }
                  if (numChars <= 0)
                      return -1;
              }
              return buf[curChar++];
          }
  
          public int Int() {
              int c = read();
              while (isSpaceChar(c))
                  c = read();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              int res = 0;
              do {
                  if (c < '0' || c > '9')
                      throw new InputMismatchException();
                  res *= 10;
                  res += c - '0';
                  c = read();
              } while (!isSpaceChar(c));
              return res * sgn;
          }
  
          public String String() {
              int c = read();
              while (isSpaceChar(c))
                  c = read();
              StringBuilder res = new StringBuilder();
              do {
                  res.appendCodePoint(c);
                  c = read();
              } while (!isSpaceChar(c));
              return res.toString();
          }
  
          public boolean isSpaceChar(int c) {
              if (filter != null)
                  return filter.isSpaceChar(c);
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
          public String next() {
              return String();
          }
  
          public interface SpaceCharFilter {
              public boolean isSpaceChar(int ch);
          }
      }
  
      static class OutputWriter {
          private final PrintWriter writer;
  
          public OutputWriter(OutputStream outputStream) {
              writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
          }
  
          public OutputWriter(Writer writer) {
              this.writer = new PrintWriter(writer);
          }
  
          public void print(Object... objects) {
              for (int i = 0; i < objects.length; i++) {
                  if (i != 0)
                      writer.print(' ');
                  writer.print(objects[i]);
              }
          }
  
          public void printLine(Object... objects) {
              print(objects);
              writer.println();
          }
  
          public void close() {
              writer.close();
          }
  
          public void flush() {
              writer.flush();
          }
      }
  
      static InputReader in = new InputReader(System.in);
      static OutputWriter out = new OutputWriter(System.out);
  
      public static long[] sort(long[] a2) {
          int n = a2.length;
          ArrayList<Long> l = new ArrayList<>();
          for (long i : a2)
              l.add(i);
          Collections.sort(l);
          for (int i = 0; i < l.size(); i++)
              a2[i] = l.get(i);
          return a2;
      }
  
      public static long pow(long x, long y) {
          long res = 1;
          while (y > 0) {
              if (y % 2 != 0) {
                  res = (res * x);// % modulus;
                  y--;
  
              }
              x = (x * x);// % modulus;
              y = y / 2;
          }
          return res;
      }
  
      // GCD___+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
      public static long gcd(long x, long y) {
          if (x == 0)
              return y;
          else
              return gcd(y % x, x);
      }
      // ******LOWEST COMMON MULTIPLE
      // *********************************************
  
      public static long lcm(long x, long y) {
          return (x * (y / gcd(x, y)));
      }
  
      // INPUT PATTERN********************************************************
      public static int i() {
          return in.Int();
      }
  
      public static long l() {
          String s = in.String();
          return Long.parseLong(s);
      }
  
      public static String s() {
          return in.String();
      }
  
      public static int[] readArray(int n) {
          int A[] = new int[n];
          for (int i = 0; i < n; i++) {
              A[i] = i();
          }
          return A;
      }
  
      public static long[] readArrayL(int n) {
          long A[] = new long[n];
          for (int i = 0; i < n; i++) {
              A[i] = l();
          }
          return A;
      }
  
  }