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: /**
   * Created by Himanshu
   **/
  
  import java.util.*;
  import java.io.*;
  import java.math.*;
  
  public class C1594 {
      public static void main(String[] args) throws IOException {
          PrintWriter out = new PrintWriter(System.out);
          Reader s = new Reader();
          int t = s.i();
          while (t-- > 0) {
              int n = s.i();
              char d = s.s().charAt(0);
              char [] arr = s.s().toCharArray();
              int count = 0;
              for (char c : arr) {
                  if (c == d) {
                      count ++;
                  }
              }
              if (count == n) {
                  out.println(0);
                  continue;
              }
              int ans = -1;
              for (int i=n/2;i<n;i++) {
                  if (arr[i] == d) {
                      ans = i+1;
                      break;
                  }
              }
              if (ans != -1) {
                  out.println(1);
                  out.println(ans);
              } else {
                  out.println(2);
                  out.println((n-1) + " " + n);
              }
          }
          out.flush();
      }
  
      public static void shuffle(long[] arr) {
          int n = arr.length;
          Random rand = new Random();
          for (int i = 0; i < n; i++) {
              long temp = arr[i];
              int randomPos = i + rand.nextInt(n - i);
              arr[i] = arr[randomPos];
              arr[randomPos] = temp;
          }
      }
  
      private static long phi(long n) {
          long result = n;
          for (long i = 2; i * i <= n; i++) {
              if (n % i == 0) {
                  while (n % i == 0)
                      n /= i;
                  result -= result / i;
              }
          }
          if (n > 1)
              result -= result / n;
          return result;
      }
  
      private static int gcd(int a, int b) {
          if(b == 0) return a;
          return gcd(b,a%b);
      }
  
      public static long nCr(long[] fact, long[] inv, int n, int r, long mod) {
          if (n < r)
              return 0;
          return ((fact[n] * inv[n - r]) % mod * inv[r]) % mod;
      }
  
      private static void factorials(long[] fact, long[] inv, long mod, int n) {
          fact[0] = 1;
          inv[0] = 1;
          for (int i = 1; i <= n; ++i) {
              fact[i] = (fact[i - 1] * i) % mod;
              inv[i] = power(fact[i], mod - 2, mod);
          }
      }
  
      private static long power(long a, long n, long p) {
          long result = 1;
          while (n > 0) {
              if (n % 2 == 0) {
                  a = (a * a) % p;
                  n /= 2;
              } else {
                  result = (result * a) % p;
                  n--;
              }
          }
          return result;
      }
  
      private static long power(long a, long n) {
          long result = 1;
          while (n > 0) {
              if (n % 2 == 0) {
                  a = (a * a);
                  n /= 2;
              } else {
                  result = (result * a);
                  n--;
              }
          }
          return result;
      }
  
      private static long query(long[] tree, int in, int start, int end, int l, int r) {
          if (start >= l && r >= end) return tree[in];
          if (end < l || start > r) return 0;
          int mid = (start + end) / 2;
          long x = query(tree, 2 * in, start, mid, l, r);
          long y = query(tree, 2 * in + 1, mid + 1, end, l, r);
          return x + y;
      }
  
      private static void update(int[] arr, long[] tree, int in, int start, int end, int idx, int val) {
          if (start == end) {
              tree[in] = val;
              arr[idx] = val;
              return;
          }
          int mid = (start + end) / 2;
          if (idx > mid) update(arr, tree, 2 * in + 1, mid + 1, end, idx, val);
          else update(arr, tree, 2 * in, start, mid, idx, val);
          tree[in] = tree[2 * in] + tree[2 * in + 1];
      }
  
      private static void build(int[] arr, long[] tree, int in, int start, int end) {
          if (start == end) {
              tree[in] = arr[start];
              return;
          }
          int mid = (start + end) / 2;
          build(arr, tree, 2 * in, start, mid);
          build(arr, tree, 2 * in + 1, mid + 1, end);
          tree[in] = (tree[2 * in + 1] + tree[2 * in]);
      }
  
      static class Reader {
          private InputStream mIs;
          private byte[] buf = new byte[1024];
          private int curChar, numChars;
  
          public Reader() {
              this(System.in);
          }
  
          public Reader(InputStream is) {
              mIs = is;
          }
  
          public int read() {
              if (numChars == -1) throw new InputMismatchException();
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = mIs.read(buf);
                  } catch (IOException e) {
                      throw new InputMismatchException();
                  }
                  if (numChars <= 0) return -1;
              }
              return buf[curChar++];
          }
  
          public String nextLine() {
              int c = read();
              while (isSpaceChar(c)) c = read();
              StringBuilder res = new StringBuilder();
              do {
                  res.appendCodePoint(c);
                  c = read();
              } while (!isEndOfLine(c));
              return res.toString();
          }
  
          public String s() {
              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 long l() {
              int c = read();
              while (isSpaceChar(c)) c = read();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              long 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 int i() {
              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 double d() throws IOException {
              return Double.parseDouble(s());
          }
  
          public boolean isSpaceChar(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
          public boolean isEndOfLine(int c) {
              return c == '\n' || c == '\r' || c == -1;
          }
  
          public int[] arr(int n) {
              int[] ret = new int[n];
              for (int i = 0; i < n; i++) {
                  ret[i] = i();
              }
              return ret;
          }
  
          public long[] arrLong(int n) {
              long[] ret = new long[n];
              for (int i = 0; i < n; i++) {
                  ret[i] = l();
              }
              return ret;
          }
      }
  //    static class pairLong implements Comparator<pairLong> {
  //        long first, second;
  //
  //        pairLong() {
  //        }
  //
  //        pairLong(long first, long second) {
  //            this.first = first;
  //            this.second = second;
  //        }
  //
  //        @Override
  //        public int compare(pairLong p1, pairLong p2) {
  //            if (p1.first == p2.first) {
  //                if(p1.second > p2.second) return 1;
  //                else return -1;
  //            }
  //            if(p1.first > p2.first) return 1;
  //            else return -1;
  //        }
  //    }
  //    static class pair implements Comparator<pair> {
  //        int first, second;
  //
  //        pair() {
  //        }
  //
  //        pair(int first, int second) {
  //            this.first = first;
  //            this.second = second;
  //        }
  //
  //        @Override
  //        public int compare(pair p1, pair p2) {
  //            if (p1.first == p2.first) return p1.second - p2.second;
  //            return p1.first - p2.first;
  //        }
  //    }
  }
  
  