Problem: Ashish has two strings a and b, each of length n, and an integer k. The strings only contain lowercase English letters.

He wants to convert string a into string b by performing some (possibly zero) operations on a.

In one move, he can either 

  * choose an index i (1 ≤ i≤ n-1) and swap a_i and a_{i+1}, or 
  * choose an index i (1 ≤ i ≤ n-k+1) and if a_i, a_{i+1}, …, a_{i+k-1} are all equal to some character c (c ≠ 'z'), replace each one with the next character (c+1), that is, 'a' is replaced by 'b', 'b' is replaced by 'c' and so on. 



Note that he can perform any number of operations, and the operations can only be performed on string a. 

Help Ashish determine if it is possible to convert string a into b after performing some (possibly zero) operations on it.

Input

The first line contains a single integer t (1 ≤ t ≤ 10^5) — the number of test cases. The description of each test case is as follows.

The first line of each test case contains two integers n (2 ≤ n ≤ 10^6) and k (1 ≤ k ≤ n).

The second line of each test case contains the string a of length n consisting of lowercase English letters.

The third line of each test case contains the string b of length n consisting of lowercase English letters.

It is guaranteed that the sum of values n among all test cases does not exceed 10^6.

Output

For each test case, print "Yes" if Ashish can convert a into b after some moves, else print "No".

You may print the letters of the answer in any case (upper or lower).

Example

Input


4
3 3
abc
bcd
4 2
abba
azza
2 1
zz
aa
6 2
aaabba
ddddcc


Output


No
Yes
No
Yes

Note

In the first test case it can be shown that it is impossible to convert a into b.

In the second test case,

"abba" \xrightarrow{inc} "acca" \xrightarrow{inc} … \xrightarrow{inc} "azza".

Here "swap" denotes an operation of the first type, and "inc" denotes an operation of the second type.

In the fourth test case,

"aaabba" \xrightarrow{swap} "aaabab" \xrightarrow{swap} "aaaabb" \xrightarrow{inc} … \xrightarrow{inc} "ddaabb" \xrightarrow{inc} … \xrightarrow{inc} "ddddbb" \xrightarrow{inc} … \xrightarrow{inc} "ddddcc".

Solution (in JAVA):

Solution:

import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;
import java.io.*;
import java.math.*;

public class CC
{
    static class pair implements Comparable<pair>
    {
        int x;
        long y;
        pair(int x,long y)
        {
            this.x=x;
            this.y=y;
        }
        public int compareTo(pair o)
        {
            return (int)(y-o.y);
        }

    }
    static ArrayList<Long>num=new ArrayList<>();
    static void printPermutn(String str, String ans)
    {

        // If string is empty
        if (str.length() == 0) {
            num.add(Long.valueOf(ans));
            return;
        }

        for (int i = 0; i < str.length(); i++)
        {

            // ith character of str
            char ch = str.charAt(i);

            // Rest of the string after excluding
            // the ith character
            String ros = str.substring(0, i) +
                    str.substring(i + 1);

            // Recurvise call
            printPermutn(ros, ans + ch);
        }
    }

    public static void main(String[] args)
    {
        StringBuffer sb = new StringBuffer();

        int t=i();
        while (t-->0)
        {
        int N=i();
        int K=i();
        char A[]=s().toCharArray();
        char B[]=s().toCharArray();

        int AA[]=new int[26];
        int BB[]=new int[26];
            for(char c:A)
            {
               int vv=(int)(c-'a');
               AA[vv]++;
            }
            for(char c:B)
            {
                int vv=(int)(c-'a');
                BB[vv]++;
            }
            int flag=0;
            for(int i=0;i<26;i++)
            {
                if(AA[i]>BB[i]&&i!=25)
                {
                    if((AA[i]-BB[i])%K!=0)
                        flag=1;
                    else {
                        AA[i+1]+=AA[i]-BB[i];
                        AA[i]=BB[i];
                    }
                }
                else  if(AA[i]<BB[i]){
                    flag=2;
                }
            }
            if(flag==0)
                sb.append("YES"+"\n");
            else
                sb.append("NO"+"\n");











        }



        System.out.println(sb.toString());
    }


 //********************************Class pair******************************************************************************************************************************************///////////////////////////////////////////////////////////////////////////////////////////////

//-------------------prime factorization********/***************************************************************************************************************************************///////////////////////////////////
static TreeMap primefactorize(long n)
{
    TreeMap<Integer,Integer>h=new TreeMap<>();
    long number=n;
    for(int i=2;i<=Math.sqrt(n);i++)
    {
        if(n%i==0)
        {
            int cnt=0;
            while(n%i==0)
            {
                n=n/i;
                cnt++;
            }
            h.put(i,cnt);
        }
    }
    if(n!=1)
        h.put((int)n,1);
    return h;
}
///******************************SYSTEM PART*****************************************************************************************************************************************************************************************************************************************************////
    static InputReader in=new InputReader(System.in);
    static OutputWriter out=new OutputWriter(System.out);

    public static long pow(long a, long b)
    {
        long result=1;
        while(b>0){
            if (b % 2 != 0){
                result=(result*a);
                b--;
            }
            a=(a*a);
            b /= 2;
        }
        return result;
    }
    public static long gcd(long a, long b){
        if (a == 0){
            return b;
        }
        return gcd(b%a, a);
    }
    public static long lcm(long a, long b){
        return a*(b/gcd(a,b));
    }
    public static long l(){
        String s=in.String();
        return Long.parseLong(s);
    }
    public static void pln(String value){
        System.out.println(value);
    }
    public static int i(){
        return in.Int();
    }
    public static String s(){
        return in.String();
    }
}
///******************input Reader//***************************************************************************************************************************************************************************************
class InputReader
{
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;
    public InputReader(InputStream stream) {
        this.stream = stream;
    }
    public int read() {
        if (numChars== -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }
    public int Int() {
        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 String String() {
        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 boolean isSpaceChar(int c) {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
    public String next() {
        return String();
    }
    public interface SpaceCharFilter
    {
        public boolean isSpaceChar(int ch);
    }
}

//*******************OUTPUT WRITER********************************************************************************************************************************************************************************************************************************************************//
class OutputWriter {
    private final PrintWriter writer;
    public OutputWriter(OutputStream outputStream) {
        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }
    public OutputWriter(Writer writer) {
        this.writer = new PrintWriter(writer);
    }
    public void print(Object...objects) {
        for (int i = 0; i < objects.length; i++) {
            if (i != 0)
                writer.print(' ');
            writer.print(objects[i]);
        }
    }
    public void printLine(Object...objects) {
        print(objects);
        writer.println();
    }
    public void close() {
        writer.close();
    }
    public void flush() {
        writer.flush();
    }
}