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: /*
  ⠀⠀⠀⠀⣠⣶⡾⠏⠉⠙⠳⢦⡀⠀⠀⠀⢠⠞⠉⠙⠲⡀⠀
  ⠀⠀⠀⣴⠿⠏⠀⠀⠀⠀⠀⠀⢳⡀⠀⡏⠀⠀Y⠀⠀⢷
  ⠀⠀⢠⣟⣋⡀⢀⣀⣀⡀⠀⣀⡀⣧⠀⢸⠀⠀A⠀⠀ ⡇
  ⠀⠀⢸⣯⡭⠁⠸⣛⣟⠆⡴⣻⡲⣿⠀⣸⠀⠀S⠀  ⡇
  ⠀⠀⣟⣿⡭⠀⠀⠀⠀⠀⢱⠀⠀⣿⠀⢹⠀⠀H⠀⠀ ⡇
  ⠀⠀⠙⢿⣯⠄⠀⠀⠀⢀⡀⠀⠀⡿⠀⠀⡇⠀⠀⠀⠀⡼
  ⠀⠀⠀⠀⠹⣶⠆⠀⠀⠀⠀⠀⡴⠃⠀⠀⠘⠤⣄⣠⠞⠀
  ⠀⠀⠀⠀⠀⢸⣷⡦⢤⡤⢤⣞⣁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
  ⠀⠀⢀⣤⣴⣿⣏⠁⠀⠀⠸⣏⢯⣷⣖⣦⡀⠀⠀⠀⠀⠀⠀
  ⢀⣾⣽⣿⣿⣿⣿⠛⢲⣶⣾⢉⡷⣿⣿⠵⣿⠀⠀⠀⠀⠀⠀
  ⣼⣿⠍⠉⣿⡭⠉⠙⢺⣇⣼⡏⠀⠀⠀⣄⢸⠀⠀⠀⠀⠀⠀
  ⣿⣿⣧⣀⣿………⣀⣰⣏⣘⣆⣀⠀⠀
   */
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter; // System.out is a PrintStream
  import java.util.InputMismatchException;
  
  
  public class C1594 {
      private static int MOD = (int)1e9 + 7, mod = 99_82_44_353;
      private static double PI = 3.14159265358979323846;
  
      public static void main(String[] args) throws IOException {
          FasterScanner scn = new FasterScanner();
          PrintWriter out = new PrintWriter(System.out);
          loop:
          for (int tc = scn.nextInt(); tc > 0; tc--) {
              int N = scn.nextInt();
              char c = scn.nextChar();
              char[] str = scn.next().toCharArray();
              boolean flag = true;
              for (int i = 0; i < N; i++) {
                  if (str[i] != c) {
                      flag = false;
                      break;
                  }
              }
              if (flag) {
                  out.println(0);
                  continue;
              }
              inner:
              for (int i = 1; i <= N; i++) {
                  if (str[i - 1] != c) continue;
                  for (int j = i + i; j <= N; j += i) {
                      if (str[j - 1] != c) {
                          continue inner;
                      }
                  }
                  out.println("1\n" + i);
                  continue loop;
              }
              out.println("2\n" + (N - 1) + " " + N);
          }
          out.close();
      }
  
      /* ------------------- Sorting ------------------- */
      private static void ruffleSort(int[] arr) {
          // int N = arr.length;
          // Random rand = new Random();
          // for (int i = 0; i < N; i++) {
          //     int oi = rand.nextInt(N), temp = arr[i];
          //     arr[i] = arr[oi];
          //     arr[oi] = temp;
          // }
          // Arrays.sort(arr);
      }
          
      /* ------------------- Sorting ------------------- */
      
      private static boolean isPalindrome(String str) {
          for (int i = 0, j = str.length() - 1; i < j; i++, j--) {
              if (str.charAt(i) != str.charAt(j)) {
                  return false;
              }
          }
          return true;
      }
      
      private static boolean isPalindrome(char[] str) {
          for (int i = 0, j = str.length - 1; i < j; i++, j--) {
              if (str[i] != str[j]) {
                  return false;
              }
          }
          return true;
      }
      
      /* ------------------- Pair class ------------------- */
      private static class Pair implements Comparable<Pair> {
  		int x, y;
  		Pair(int x, int y) {
  			this.x = x;
  			this.y = y;
  		}
  		public int compareTo(Pair o) {
  			return this.x == o.x ? this.y - o.y : this.x - o.x;
  		}
  	}
  
      /* ------------------- HCF and LCM ------------------- */
      private static int gcd(int num1, int num2) {
          int temp = 0;
          while (num2 != 0) {
              temp = num1;
              num1 = num2;
              num2 = temp % num2;
          }
          return num1;
      }
      
      private static int lcm(int num1, int num2) {
          return (int)((1L * num1 * num2) / gcd(num1, num2));
      }
      
      /* ------------------- primes and prime factorization ------------------- */
      private static boolean[] seive(int N) {
          // true means not prime, false means is a prime number :)
          boolean[] notPrimes = new boolean[N + 1];
          notPrimes[0] = notPrimes[1] = true;
          for (int i = 2; i * i <= N; i++) {
              if (notPrimes[i]) continue;
              for (int j = i * i; j <= N; j += i) {
                  notPrimes[j] = true;
              }
          }
          return notPrimes;
      }
  
  	/*
      private static TreeMap<Integer, Integer> primeFactors(long N) {
  		TreeMap<Integer, Integer> primeFact = new TreeMap<>();
  		for (int i = 2; i <= Math.sqrt(N); i++) {
              int count = 0;
              while (N % i == 0) {
                  N /= i;
                  count++;
              }
              if (count != 0) {
                  primeFact.put(i, count);
              }
  		}
  		if (N != 1) {
              primeFact.put((int)N, 1);
          }
  		return primeFact;
  	}
      */
  
      /* ------------------- Binary Search ------------------- */
      private static long factorial(int N) {
          long ans = 1L;
          for (int i = 2; i <= N; i++) {
              ans *= i;
          }
          return ans;
      }
  
      private static long[] factorialDP(int N) {
          long[] factDP = new long[N + 1];
          factDP[0] = factDP[1] = 1;
          for (int i = 2; i <= N; i++) {
              factDP[i] = factDP[i - 1] * i;
          }
          return factDP;
      }
  
      private static long factorialMod(int N, int mod) {
          long ans = 1L;
          for (int i = 2; i <= N; i++) {
              ans = ((ans % mod) * (i % mod)) % mod;
          }
          return ans;
      }
  
      /* ------------------- Binary Search ------------------- */
      private static int floorSearch(int[] arr, int st, int ed, int tar) {
          int ans = -1;
          while (st <= ed) {
              int mid = ((ed - st) >> 1) + st;
              if (arr[mid] <= tar) {
                  ans = mid;
                  st = mid + 1;
              } else {
                  ed = mid - 1;
              }
          }
          return ans;
      }
      
      private static int ceilingSearch(int[] arr, int st, int ed, int tar) {
          int ans = -1;
          while (st <= ed) {
              int mid = ((ed - st) >> 1) + st;
              if (arr[mid] < tar) {
                  st = mid + 1;
              } else {
                  ans = mid;
                  ed = mid - 1;
              }
          }
          return ans;
      }
      
      /* ------------------- Power Function ------------------- */
      public static long pow(long x, long y) {
          long res = 1;
  		while (y > 0) {
              if ((y & 1) != 0) {
                  res = (res * x);
  				y--;
  			}
  			x = (x * x);
  			y >>= 1;
  		}
  		return res;
  	}
      
  	public static long powMod(long x, long y, int mod) {
          long res = 1;
  		while (y > 0) {
              if ((y & 1) != 0) {
                  res = (res * x) % mod;
  				y--;
  			}
  			x = (x * x) % mod;
  			y >>= 1;
  		}
  		return res % mod;
  	}
  
      /* ------------------- Disjoint Set(Union and Find) ------------------- */
      private static class DSU {
  		public int[] parent, rank;
  		DSU(int N) {
  			parent = new int[N];
  			rank = new int[N];
  			for (int i = 0; i < N; i++) {
  				parent[i] = i;
                  rank[i] = 1;
              }
  		}
  		public int find(int a) {
  			if (parent[a] == a) {
  				return a;
              }
              return parent[a] = find(parent[a]);
  		}
  		public boolean union(int a, int b) {
  			int parA = find(a), parB = find(b);
  			if (parA == parB) return false;
  			if (rank[parA] > rank[parB]) {
                  parent[parB] = parA;
              } else if (rank[parA] < rank[parB]) {
                  parent[parA] = parB;
              } else {
                  parent[parA] = parB;
                  rank[parB]++;
              }
              return true;
  		}
  	}
      
      /* ------------------- Scanner class for input ------------------- */
      
      private static class FasterScanner {
  		private InputStream stream;
  		private byte[] buffer = new byte[1024];
  		private int curChar, numChars;
  		private SpaceCharFilter filter;
  
  		public FasterScanner() {
              // default
  			this.stream = System.in;
  		}
  
  		public FasterScanner(InputStream stream) {
  			this.stream = stream;
  		}
  
  		private int readChar() {
  			if (numChars == -1) {
  				throw new InputMismatchException();
              }
  			if (curChar >= numChars) {
  				curChar = 0;
  				try {
  					numChars = stream.read(buffer);
  				} catch (IOException e) {
  					throw new InputMismatchException(e.getMessage());
  				}
  				if (numChars <= 0) {
  					return -1;
                  }
  			}
  			return buffer[curChar++];
  		}
  
  		private boolean isWhiteSpace(int c) {
  			if (filter != null) {
  				return filter.isWhiteSpace(c);
              }
  			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  		}
  
  		private boolean isNewLine(int ch) {
  			if (filter != null) {
  				return filter.isNewLine(ch);
              }
  			return ch == '\r' || ch == '\n' || ch == -1;
  		}
  
      public char nextChar() {
          int ch = readChar();
          char res = '\0';
          while (isWhiteSpace(ch)) {
              ch = readChar();
          }
          do {
              res = (char)ch;
              ch = readChar();
          } while (!isWhiteSpace(ch));
          return res;
      }
  
  		public String next() {
  			int ch = readChar();
              StringBuilder res = new StringBuilder();
  			while (isWhiteSpace(ch)) {
  				ch = readChar();
              }
  			do {
  				res.appendCodePoint(ch);
  				ch = readChar();
  			} while (!isWhiteSpace(ch));
  			return res.toString();
  		}
  
  		public String nextLine() {
  			int ch = readChar();
              StringBuilder res = new StringBuilder();
  			do {
  				res.appendCodePoint(ch);
  				ch = readChar();
  			} while (!isNewLine(ch));
  			return res.toString();
  		}
  
  		public int nextInt() {
  			int ch = -1, sgn = 1, res = 0;
              do {
                  ch = readChar();
              } while (isWhiteSpace(ch));
  			if (ch == '-') {
  				sgn = -1;
  				ch = readChar();
  			}
  			do {
  				if (ch < '0' || ch > '9') {
  					throw new InputMismatchException("not a number");
                  }
  				res = (res * 10) + (ch - '0');
  				ch = readChar();
  			} while (!isWhiteSpace(ch));
              
  			return res * sgn;
  		}
  
  		public long nextLong() {
  			int ch = -1, sgn = 1;
              long res = 0L;
              do {
                  ch = readChar();
              } while (isWhiteSpace(ch));
  			if (ch == '-') {
  				sgn = -1;
  				ch = readChar();
  			}
  			do {
  				if (ch < '0' || ch > '9') {
  					throw new InputMismatchException("not a number");
                  }
  				res = (10L * res) + (ch - '0');
  				ch = readChar();
  			} while (!isWhiteSpace(ch));
  
  			return 1L * res * sgn;
  		}
  
      public double nextDouble() {
          return Double.parseDouble(next());
      }
  
          /* for custom delimiters */
  		public interface SpaceCharFilter {
  			public boolean isWhiteSpace(int ch);
  			public boolean isNewLine(int ch);
  		}
  	}
  }
  