Problem: There are n children, who study at the school №41. It is well-known that they are good mathematicians. Once at a break, they arranged a challenge for themselves. All children arranged in a row and turned heads either to the left or to the right.

Children can do the following: in one second several pairs of neighboring children who are looking at each other can simultaneously turn the head in the opposite direction. For instance, the one who was looking at the right neighbor turns left and vice versa for the second child. Moreover, every second at least one pair of neighboring children performs such action. They are going to finish when there is no pair of neighboring children who are looking at each other. 

You are given the number n, the initial arrangement of children and the number k. You have to find a way for the children to act if they want to finish the process in exactly k seconds. More formally, for each of the k moves, you need to output the numbers of the children who turn left during this move.

For instance, for the configuration shown below and k = 2 children can do the following steps: 

<image> At the beginning, two pairs make move: (1, 2) and (3, 4). After that, we receive the following configuration:  <image> At the second move pair (2, 3) makes the move. The final configuration is reached. Good job.  <image>

It is guaranteed that if the solution exists, it takes not more than n^2 "headturns".

Input

The first line of input contains two integers n and k (2 ≤ n ≤ 3000, 1 ≤ k ≤ 3000000) — the number of children and required number of moves.

The next line contains a string of length n and consists only of characters L and R, where L means that the child looks to the left and R means that the child looks to the right. 

Output

If there is no solution, print a single line with number -1.

Otherwise, output k lines. Each line has to start with a number n_i (1≤ n_i ≤ n/2) — the number of pairs of children, who turn at this move. After that print n_i distinct integers — the numbers of the children who will turn left during this move. 

After performing all "headturns", there can't be a pair of two neighboring children looking at each other.

If there are many solutions, print any of them.

Examples

Input


2 1
RL


Output


1 1 


Input


2 1
LR


Output


-1

Input


4 2
RLRL


Output


2 1 3 
1 2

Note

The first sample contains a pair of children who look at each other. After one move, they can finish the process.

In the second sample, children can't make any move. As a result, they can't end in k>0 moves.

The third configuration is described in the statement.

Solution (in JAVA):

Solution:
import java.io.*;
import java.lang.Math;
import java.util.*;

public class Main  {

    public BufferedReader in;
    public PrintStream out;

    public boolean log_enabled = false;
    
    public boolean multiply_tests = false;

    public static boolean do_gen_test = false;
    
    public void gen_test() {
            
        
    }
    
    private class TestCase {

        public Object solve() {
            
            int i, N = readInt(), K = readInt();
            
            String s = readLn();
            
            int[] P = new int[N];
            for (i=0; i<N;i++ )
            {
                P[i] = s.charAt(i)=='L' ? 0 : 1;
            }
            
            int c = 0, k, total = 0;
            int[][] R = new int[K][];
            int[] Rc = new int[K];
            int[] R_tmp = new int[N];
            
            for (i=0; i<N-1; i++)
            {
                if ((P[i]==1)&&(P[i+1]==0))
                {
                    R_tmp[c++] = i;
                }
            }
            
            if (c==0)
            {
                return -1;
            }
            
            total += c;
            
            R[0] = new int[c];
            Rc[0] = c;
            for (i=0; i<c; i++)
            {
                R[0][i] = R_tmp[i];
            }
            
            k = 1;
            int L;
            while (true)
            {
                c = 0;
                for (i=0;i<Rc[k-1]; i++)
                {
                    L = R[k-1][i];
                    
                    P[L] = 0;
                    P[L+1] = 1;
                    
                    if ((L>0)&&(P[L-1]==1))
                    {
                        R_tmp[c++] = L-1;
                    }
                    
                    if ((L+2<N)&&(P[L+2]==0))
                    {
                        R_tmp[c++] = L+1;
                    }
                }
                
                if (c == 0)
                {
                    break;
                }
                
                if (k == K)
                {
                    return -1;
                }
                
                Rc[k] = c;
                R[k] = new int[c];
                for (i=0; i<c; i++)
                {
                    R[k][i] = R_tmp[i];
                }
                
                total += c;
                
                k++;
            }
            
            
            if (K > total)
            {
                return -1;
            }
            
            
            c = 0;
            int j,p = 0;
            
            int[] output = new int[total + K];
            int ps = 0;
            
            for (i=0; i<K; i++)
            {
                if (k-c < K-i)
                {
                    output[ps++] = -1;
                    output[ps++] = R[c][p]+1;
                    
                    
                    p ++;
                    if (p == Rc[c])
                    {
                        c++;
                        p = 0;
                    }
                }
                else
                {
                    output[ps++] = -(Rc[c]-p);
                    for (j=p; j<Rc[c]; j++)
                    {
                        output[ps++] = R[c][j]+1;
                    }
                    
                    
                    c++;
                    p = 0;
                }
            }
            
            printArray(output, total + K);
                          
            
            return null;
            
            //return strf("%f", 0);
            
            //out.printf("Case #%d: \n", caseNumber);
            //return null;
        }
        
        public int caseNumber;
        
        TestCase(int number) {
            caseNumber = number;
        }
        
        public void run(){
            Object r = this.solve();
            
            if ((r != null))
            {
                //outputCaseNumber(r);
                out.println(r);
            }
        }
        
        public String impossible(){
            return "IMPOSSIBLE";
        }
        
        public String strf(String format, Object... args)
        {
            return String.format(format, args);
        }
        
//        public void outputCaseNumber(Object r){
//            //out.printf("Case #%d:", caseNumber);
//            if (r != null)
//            {
//              //  out.print(" ");
//                out.print(r);
//            }
//            out.print("\n");
//        }
    }

    public void run() {
        //while (true)
        {
            int t = multiply_tests ?  readInt() : 1;
            for (int i = 0; i < t; i++) {
                TestCase T = new TestCase(i + 1);
                T.run();
            }
        }
    }
    

    
    public Main(BufferedReader _in, PrintStream _out){
        in = _in;
        out = _out;
    }
    

    public static void main(String args[]) {
        Locale.setDefault(Locale.US);
        Main S;
        try {
            S = new Main(
                        new BufferedReader(new InputStreamReader(System.in)),
                        System.out
                );
        } catch (Exception e) {
            return;
        }
        
        S.run();
        
    }

    private StringTokenizer tokenizer = null;

    public int readInt() {
        return Integer.parseInt(readToken());
    }

    public long readLong() {
        return Long.parseLong(readToken());
    }

    public double readDouble() {
        return Double.parseDouble(readToken());
    }

    public String readLn() {
        try {
            String s;
            while ((s = in.readLine()).length() == 0);
            return s;
        } catch (Exception e) {
            return "";
        }
    }

    public String readToken() {
        try {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                tokenizer = new StringTokenizer(in.readLine());
            }
            return tokenizer.nextToken();
        } catch (Exception e) {
            return "";
        }
    }

    public int[] readIntArray(int n) {
        int[] x = new int[n];
        readIntArray(x, n);
        return x;
    }
    
    public int[] readIntArrayBuf(int n) {
        int[] x = new int[n];
        readIntArrayBuf(x, n);
        return x;
    }

    public void readIntArray(int[] x, int n) {
        for (int i = 0; i < n; i++) {
            x[i] = readInt();
        }
    }
    
    public long[] readLongArray(int n) {
        long[] x = new long[n];
        readLongArray(x, n);
        return x;
    }
    
    public long[] readLongArrayBuf(int n) {
        long[] x = new long[n];
        readLongArrayBuf(x, n);
        return x;
    }

    public void readLongArray(long[] x, int n) {
        for (int i = 0; i < n; i++) {
            x[i] = readLong();
        }
    }

    public void logWrite(String format, Object... args) {
        if (!log_enabled) {
            return;
        }

        out.printf(format, args);
    }
    
    public void readLongArrayBuf(long[] x, int n) {
        
        char[]buf = new char[1000000];
        long r = -1;
        int k= 0, l = 0;
        long d;
        
        while (true)
        {
            try{
                l = in.read(buf, 0, 1000000);
            }
            catch(Exception E){};
            
            for (int i=0; i<l; i++)
            {
                if (('0'<=buf[i])&&(buf[i]<='9'))
                {
                    if (r == -1)
                    {
                        r = 0;
                    }
                    d = buf[i] - '0';
                    r = 10 * r + d;
                }
                else
                {
                    if (r != -1)
                    {
                        x[k++] = r;
                    }
                    
                    r = -1;
                }
            }
            
            if (l<1000000)
                return;
        }
    }
    
    public void readIntArrayBuf(int[] x, int n) {
        
        char[]buf = new char[1000000];
        int r = -1;
        int k= 0, l = 0;
        int d;
        
        while (true)
        {
            try{
                l = in.read(buf, 0, 1000000);
            }
            catch(Exception E){};
            
            for (int i=0; i<l; i++)
            {
                if (('0'<=buf[i])&&(buf[i]<='9'))
                {
                    if (r == -1)
                    {
                        r = 0;
                    }
                    d = buf[i] - '0';
                    r = 10 * r + d;
                }
                else
                {
                    if (r != -1)
                    {
                        x[k++] = r;
                    }
                    
                    r = -1;
                }
            }
            
            if (l<1000000)
                return;
        }
    }
    
    public void printArray(long[] a, int n)
    {
        printArray(a, n, ' ');
    }
    
    public void printArray(int[] a, int n)
    {
        printArray(a, n, ' ');
    }
            
    public void printArray(long[] a, int n, char dl)
    {
        long x; 
        int i, l = 0;
        for (i=0; i<n; i++)
        {
            x = a[i];
            
            if (x<0)
            {
                x = -x;
                l++;
            }
            
            if (x==0)
            {
                l++;
            }
            else
            {
                while (x>0)
                {
                    x /= 10;
                    l++;
                }
            }
        }
        
        l += n-1;
        
        char[] s = new char[l];
        
        l--;
        boolean z;
        for (i=n-1; i>=0;  i--)
        {
            x = a[i];
            z = false;            
            if (x<0)
            {
                x = -x;
                z = true;
            }
            
            do{
                s[l--] = (char)('0' + (x % 10));
                x /= 10;
            } while (x>0);
            
            if (z)
            {
                s[l--] = '-';
            }
            
            if (i>0)
            {
                s[l--] = dl;
            }
        }
        
        out.println(new String(s));
    }
    
    public void printArray(int[] a, int n, char dl)
    {
        int x; 
        int i, l = 0;
        for (i=0; i<n; i++)
        {
            x = a[i];
            
            if (x<0)
            {
                x = -x;
            }
            
            if (x==0)
            {
                l++;
            }
            else
            {
                while (x>0)
                {
                    x /= 10;
                    l++;
                }
            }
        }
        
        l += n-1;
        
        char[] s = new char[l];
        
        l--;
        boolean z;
        for (i=n-1; i>=0;  i--)
        {
            x = a[i];
            z = false;            
            if (x<0)
            {
                x = -x;
                z = true;
            }
            
            do{
                s[l--] = (char)('0' + (x % 10));
                x /= 10;
            } while (x>0);
            
            if (i>0)
            {
                s[l--] = z ? '\n' : dl;
            }
        }
        
        out.println(new String(s));
    }
    
    public void printMatrix(int[][] a, int n, int m)
    {
        int x; 
        int i,j, l = 0;
        for (i=0; i<n; i++)
        {
            for (j=0; j<m; j++)
            {
                x = a[i][j];
            
                if (x<0)
                {
                    x = -x;
                    l++;
                }

                if (x==0)
                {
                    l++;
                }
                else
                {
                    while (x>0)
                    {
                        x /= 10;
                        l++;
                    }
                }
            }
            
            l += m-1;
        }
        
        l += n-1;
        
        
        char[] s = new char[l];
        
        l--;
        boolean z;
        for (i=n-1; i>=0;  i--)
        {
            for (j=m-1; j>=0;  j--)
            {
                x = a[i][j];
                z = false;            
                if (x<0)
                {
                    x = -x;
                    z = true;
                }

                do{
                    s[l--] = (char)('0' + (x % 10));
                    x /= 10;
                } while (x>0);

                if (z)
                {
                    s[l--] = '-';
                }

                if (j>0)
                {
                    s[l--] = ' ';
                }
            }
            
            if (i>0)
            {
                 s[l--] = '\n';
            }
        }
        
        out.println(new String(s));
    }
    
    public void printMatrix(long[][] a, int n, int m)
    {
        long x; 
        int i,j, l = 0;
        for (i=0; i<n; i++)
        {
            for (j=0; j<m; j++)
            {
                x = a[i][j];
            
                if (x<0)
                {
                    x = -x;
                    l++;
                }

                if (x==0)
                {
                    l++;
                }
                else
                {
                    while (x>0)
                    {
                        x /= 10;
                        l++;
                    }
                }
            }
            
            l += m-1;
        }
        
        l += n-1;
        
        
        char[] s = new char[l];
        
        l--;
        boolean z;
        for (i=n-1; i>=0;  i--)
        {
            for (j=m-1; j>=0;  j--)
            {
                x = a[i][j];
                z = false;            
                if (x<0)
                {
                    x = -x;
                    z = true;
                }

                do{
                    s[l--] = (char)('0' + (x % 10));
                    x /= 10;
                } while (x>0);

                if (z)
                {
                    s[l--] = '-';
                }

                if (j>0)
                {
                    s[l--] = ' ';
                }
            }
            
            if (i>0)
            {
                 s[l--] = '\n';
            }
        }
        
        out.println(new String(s));
    }
    
    
}