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.io.*;
  import java.util.*;
  
  
  public class Practice
  {
  //	static final long mod=7420738134811L;
  	static int mod=1000000007;
  	static final int size=300001;
  	static FastReader sc=new FastReader(System.in);
  //	static Reader sc=new Reader();
  	static  PrintWriter out=new PrintWriter(System.out);
  //	static {
  //		try {
  //			sc = new FastReader(new FileInputStream("input.txt"));
  //			out = new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
  //		} catch (Exception e) {}
  //	}
  	static long[] factorialNumInverse;
  	static long[] naturalNumInverse;	
  	static int[] prime;
  	static long[] fact;
  	static ArrayList<Integer> pr;
  	public static void main(String[] args) throws IOException
  	{
  //		System.setIn(new FileInputStream("input.txt"));
  //		System.setOut(new PrintStream("output.txt"));
  //		factorial(mod);
  //		InverseofNumber(mod);
  //		InverseofFactorial(mod);
  //		make_seive();
  		int t=1;
  		t=sc.nextInt();
  		while(t-->0)
  			solve();
  		out.close();
  		out.flush();
  	}
  	static void solve() throws IOException
  	{
  		int n=sc.nextInt();
  		char ch=sc.next().trim().charAt(0);
  		String str=sc.next();
  		boolean f=true;
  		for(int i=0;i<n;i++)
  			if(str.charAt(i)!=ch)
  				f=false;
  		if(f)
  		{
  			out.println("0");
  			return;
  		}
  		int pos=0;
  		for(int i=n/2;i<n;i++)
  		if(str.charAt(i)==ch)
  		{
  			f=true;
  			pos=i+1;
  			break;
  		}
  		if(f)
  		{
  			out.println("1");	
  			out.println(pos);				
  		}
  		else
  		{
  			out.println("2");
  			out.println(n+" "+(n-1));				
  		}
  	}
  	static class Pair implements Cloneable, Comparable<Pair>
  	{
  		int x,y;
  		Pair(int a,int b)
  		{
  			this.x=a;
  			this.y=b;
  		}
  		@Override
  		public String toString() 
  		{
  			return "("+x+","+(y)+")";
  		}
  		@Override
  		protected Pair clone() throws CloneNotSupportedException {
  			return new Pair(this.x,this.y);
  		}
  		@Override
  		public int compareTo(Pair a) 
  		{
  			return a.x-this.x;
  		}
  		
  	}
  	static class Tuple implements Cloneable
  	{
  		int x,y,z;
  		Tuple(int a,int b,int c)
  		{
  			this.x=a;
  			this.y=b;
  			this.z=c;
  		}
  		@Override
  		public String toString() 
  		{
  			return "("+x+","+y+","+z+")";
  		}
  		@Override
  		protected Tuple clone() throws CloneNotSupportedException {
  			return new Tuple(this.x,this.y,this.z);
  		}
  	}
  	static void arraySort(int arr[])
  	{
  		ArrayList<Integer> a=new ArrayList<Integer>();
  		for (int i = 0; i < arr.length; i++) {
  			a.add(arr[i]);
  		}
  		Collections.sort(a);
  		for (int i = 0; i < arr.length; i++) {
  			arr[i]=a.get(i);
  		}
  	}
  	static void arraySort(long arr[])
  	{
  		ArrayList<Long> a=new ArrayList<Long>();
  		for (int i = 0; i < arr.length; i++) {
  			a.add(arr[i]);
  		}
  		Collections.sort(a);
  		for (int i = 0; i < arr.length; i++) {
  			arr[i]=a.get(i);
  		}
  	}
  	static HashSet<Integer> findFactors(int n)
  	{
  		HashSet<Integer> ans=new HashSet<Integer>();
  		if(n%2==0)
  		{
  			ans.add(2);
  			while((n&1)==0)
  				n=n>>1;
  		}
  		for(int i=3;i*i<=n;i+=2)
  		{
  			if(n%i==0)
  			{
  				ans.add(i);
  				while(n%i==0)
  					n=n/i;
  			}
  		}
  		if(n!=1)
  			ans.add(n);
  		return ans;
  	}
  	static void make_seive()
  	{
  		prime=new int[size];
  		pr=new ArrayList<Integer>();
  		for (int i=2; i<size; ++i) {
  		    if (prime[i] == 0) {
  		        prime[i] = i;
  		        pr.add(i);
  		    }
  		    for (int j=0; j<(int)pr.size() && pr.get(j)<=prime[i] && i*pr.get(j)<size; ++j)
  		        prime[i * pr.get(j)] = pr.get(j);
  		}
  	}
  	static class fwtSUM
  	{}
  	public static void InverseofNumber(int p)
  	{
  		naturalNumInverse=new long[size];
  	    naturalNumInverse[0] = naturalNumInverse[1] = 1;
  	    for(int i = 2; i < size; i++)
  	        naturalNumInverse[i] = naturalNumInverse[p % i] * (long)(p - p / i) % p;
  	}
  	// Function to precompute inverse of factorials
  	public static void InverseofFactorial(int p)
  	{
  		factorialNumInverse=new long[size];
  	    factorialNumInverse[0] = factorialNumInverse[1] = 1;
  	    // pre-compute inverse of natural numbers
  	    for(int i = 2; i < size; i++)
  	        factorialNumInverse[i] = (naturalNumInverse[i] * factorialNumInverse[i - 1]) % p;
  	}
  	// Function to calculate factorial of 1 to 200001
  	public static void factorial(int p)
  	{
  		fact=new long[size];
  	    fact[0] = 1;
  	    for(int i = 1; i < size; i++)
  	        fact[i] = (fact[i - 1] * (long)i) % p;
  	}
  	 
  	// Function to return nCr % p in O(1) time
  	public static long Binomial(int N, int R, int p)
  	{
  	    // n C r = n!*inverse(r!)*inverse((n-r)!)
  	    long ans = ((fact[N] * factorialNumInverse[R]) % p * factorialNumInverse[N - R]) % p;
  	    return ans;
  	}
  	static int findXOR(int x)	//from 0 to x
  	{
  		if(x<0)
  			return 0;
  		if(x%4==0)
  			return x;
  		if(x%4==1)
  			return 1;
  		if(x%4==2)
  			return x+1;
  		return 0;
  	}
  	static boolean isPrime(long x)
  	{
  		if(x==1)
  			return false;
  		if(x<=3)
  			return true;
  		if(x%2==0 || x%3==0)
  			return false;
  		for(int i=5;i<=Math.sqrt(x);i+=2)
  			if(x%i==0)
  				return false;
  		return true;
  	}
  	static long gcd(long a,long b)
  	{
  		return (b==0)?a:gcd(b,a%b);
  	}
  	static int gcd(int a,int b)
  	{
  		return (b==0)?a:gcd(b,a%b);
  	}
  	static class Node
  	{
  		int vertex,value;
  		ArrayList<Node> adj;
  		int xorSubtree=0,begin,end;
  		Node(int ver,int val)
  		{
  			vertex=ver;
  			value=val;
  			xorSubtree=0;
  			begin=0;
  			end=0;
  			adj=new ArrayList<Node>();
  		}
  		@Override
  		public String toString() 
  		{
  			return vertex+" ";
  		}
  	}
  	static class Edge
  	{
  		Node to;
  		int cost;
  		Edge(Node t,int c)
  		{
  			this.to=t;
  			this.cost=c;
  		}
  		@Override
  		public String toString() {
  			return "("+to.vertex+","+cost+") ";
  		}
  	}
  	static long power(long x, long y)
  	  {
  	    long res = 1; 
  	    x = x % mod; 
  	    if (x == 0)
  	      return 0; 
  	    while (y > 0)
  	    {
  	    	if ((y & 1) != 0)
  	    		res = (res * x) % mod;
  	    	
  	    	y = y >> 1; // y = y/2
  	    	x = (x * x) % mod;
  	    }
  	    return res;
  	  }
  	static long binomialCoeff(long n, long k)
      {
          long res = 1;
  //        if(k>n)
  //        	return 0;
          // Since C(n, k) = C(n, n-k)
          if (k > n - k)
              k = n - k;
   
          // Calculate value of
          // [n * (n-1) *---* (n-k+1)] / [k * (k-1) *----* 1]
          for (long i = 0; i < k; ++i) {
              res *= (n - i);
              res /= (i + 1);
          }
   
          return res;
      }
  	static class FastReader
  	{
          byte[] buf = new byte[2048];
          int index, total;
          InputStream in;
   
          FastReader(InputStream is) 
          {
              in = is;
          }
   
          int scan() throws IOException 
          {
              if (index >= total) {
                  index = 0;
                  total = in.read(buf);
                  if (total <= 0) {
                      return -1;
                  }
              }
              return buf[index++];
          }
   
          String next() throws IOException 
          {
              int c;
              for (c = scan(); c <= 32; c = scan());
              StringBuilder sb = new StringBuilder();
              for (; c > 32; c = scan()) {
                  sb.append((char) c);
              }
              return sb.toString();
          }
   
          int nextInt() throws IOException 
          {
              int c, val = 0;
              for (c = scan(); c <= 32; c = scan());
              boolean neg = c == '-';
              if (c == '-' || c == '+') {
                  c = scan();
              }
              for (; c >= '0' && c <= '9'; c = scan()) {
                  val = (val << 3) + (val << 1) + (c & 15);
              }
              return neg ? -val : val;
          }
   
          long nextLong() throws IOException 
          {
              int c;
              long val = 0;
              for (c = scan(); c <= 32; c = scan());
              boolean neg = c == '-';
              if (c == '-' || c == '+') {
                  c = scan();
              }
              for (; c >= '0' && c <= '9'; c = scan()) {
                  val = (val << 3) + (val << 1) + (c & 15);
              }
              return neg ? -val : val;
          }
      }
  	static class Reader 
  	{
          final private int BUFFER_SIZE = 1 << 16;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
   
          public Reader()
          {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public Reader(String file_name) throws IOException
          {
              din = new DataInputStream(
                  new FileInputStream(file_name));
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public String readLine() throws IOException
          {
              byte[] buf = new byte[64]; // line length
              int cnt = 0, c;
              while ((c = read()) != -1) {
                  if (c == '\n') {
                      if (cnt != 0) {
                          break;
                      }
                      else {
                          continue;
                      }
                  }
                  buf[cnt++] = (byte)c;
              }
              return new String(buf, 0, cnt);
          }
   
          public int nextInt() throws IOException
          {
              int ret = 0;
              byte c = read();
              while (c <= ' ') {
                  c = read();
              }
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          public long nextLong() throws IOException
          {
              long ret = 0;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg)
                  return -ret;
              return ret;
          }
   
          public double nextDouble() throws IOException
          {
              double ret = 0, div = 1;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
   
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (c == '.') {
                  while ((c = read()) >= '0' && c <= '9') {
                      ret += (c - '0') / (div *= 10);
                  }
              }
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          private void fillBuffer() throws IOException
          {
              bytesRead = din.read(buffer, bufferPointer = 0,
                                   BUFFER_SIZE);
              if (bytesRead == -1)
                  buffer[0] = -1;
          }
   
          private byte read() throws IOException
          {
              if (bufferPointer == bytesRead)
                  fillBuffer();
              return buffer[bufferPointer++];
          }
   
          public void close() throws IOException
          {
              if (din == null)
                  return;
              din.close();
          }
          public void printarray(int arr[])
          {
          	for (int i = 0; i < arr.length; i++)
  				System.out.print(arr[i]+" ");
          	System.out.println();
          }
      }
  }
  
  
  
  
  
  
  
  