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.*;
  
  public class C {
  
      public void prayGod() throws IOException {
          int t = nextInt();
          while (t-- > 0) {
              int n = nextInt();
              char c = next().charAt(0);
              String s = next();
  
              int cnt = 0;
  
              for (int i = 0; i < n; i++) {
                  if (s.charAt(i) != c) {
                      cnt++;
                  }
              }
  
              if (cnt <= 0) {
                  out.println(0);
                  continue;
              }
  
              boolean oneStep = false;
              int oneVal = -1;
  
              for (int i = 0; i < n; i++) {
                  int currCount = 0;
                  for (int j = i; j < n; j += (i + 1)) {
                      if (s.charAt(j) != c)
                          currCount++;
                  }
                  if (currCount == 0) {
                      oneStep = true;
                      oneVal = i + 1;
                      break;
                  }
              }
  
              if (oneStep) {
                  out.printf("1\n%d\n", oneVal);
              } else {
                  out.printf("2\n%d %d\n", n, n - 1);
              }
  
          }
      }
  
      public long binpow(long a, long b) {
          if (b == 0)
              return 1;
          if (b == 1)
              return a;
          long ret = binpow(a, b / 2);
          ret *= ret;
          ret %= mod;
          if (b % 2 == 1)
              ret *= a;
          return ret % mod;
      }
  
      public void printVerdict(boolean verdict) {
          if (verdict)
              out.println(VERDICT_YES);
          else
              out.println(VERDICT_NO);
      }
  
      static final String VERDICT_YES = "YES";
      static final String VERDICT_NO = "NO";
      static final boolean RUN_TIMING = true;
      static final boolean AUTOFLUSH = false;
      static final boolean FILE_INPUT = false;
      static final boolean FILE_OUTPUT = false;
  
      static int iinf = 0x3f3f3f3f;
      static long inf = (long) 1e18 + 10;
      static int mod = (int) 1e9 + 7;
  
      static char[] inputBuffer = new char[1 << 20];
      static PushbackReader in = new PushbackReader(new BufferedReader(new InputStreamReader(System.in)), 1 << 20);
      static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)), AUTOFLUSH);
  
      // int data-type
      public int nextInt() throws IOException {
          return Integer.parseInt(next());
      }
  
      public int[] nextIntArray(int n) throws IOException {
          int[] arr = new int[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextInt();
          return arr;
      }
  
      public void sort(int[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static void printArray(int[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // long data-type
      public long nextLong() throws IOException {
          return Long.parseLong(next());
      }
  
      public long[] nextLongArray(int n) throws IOException {
          long[] arr = new long[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextLong();
          return arr;
      }
  
      public static void printArray(long[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public void sort(long[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      // double data-type
      public double nextDouble() throws IOException {
          return Double.parseDouble(next());
      }
  
      public double[] nextDoubleArray(int n) throws IOException {
          double[] arr = new double[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextDouble();
          return arr;
      }
  
      public static void printArray(double[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // Generic type
      public <T> void sort(T[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static <T> void printArray(T[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public String next() throws IOException {
          int len = 0;
          int c;
          do {
              c = in.read();
          } while (Character.isWhitespace(c) && c != -1);
          if (c == -1) {
              throw new NoSuchElementException("Reached EOF");
          }
          do {
              inputBuffer[len] = (char) c;
              len++;
              c = in.read();
          } while (!Character.isWhitespace(c) && c != -1);
          while (c != '\n' && Character.isWhitespace(c) && c != -1) {
              c = in.read();
          }
          if (c != -1 && c != '\n') {
              in.unread(c);
          }
          return new String(inputBuffer, 0, len);
      }
  
      public String nextLine() throws IOException {
          int len = 0;
          int c;
          while ((c = in.read()) != '\n' && c != -1) {
              if (c == '\r') {
                  continue;
              }
              inputBuffer[len] = (char) c;
              len++;
          }
          return new String(inputBuffer, 0, len);
      }
  
      public boolean hasNext() throws IOException {
          String line = nextLine();
          if (line.isEmpty()) {
              return false;
          }
          in.unread('\n');
          in.unread(line.toCharArray());
          return true;
      }
  
      public void shuffle(int[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              int temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(long[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              long temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(Object[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              Object temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public static void main(String[] args) throws IOException {
          if (FILE_INPUT)
              in = new PushbackReader(new BufferedReader(new FileReader(new File("output.txt"))), 1 << 20);
          if (FILE_OUTPUT)
              out = new PrintWriter(new FileWriter(new File("output.txt")));
  
          long time = 0;
          time -= System.nanoTime();
          new C().prayGod();
          time += System.nanoTime();
  
          if (RUN_TIMING)
              System.err.printf("%.3f ms%n", time / 1000000.0);
  
          out.flush();
          in.close();
      }
  }