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.io.*;
public class C{
    static class InputReader {

        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int snext() {
            if (snumChars == -1)
                throw new InputMismatchException();
            if (curChar >= snumChars) {
                curChar = 0;
                try {
                    snumChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (snumChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = snext();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long nextLong() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = snext();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public int[] nextIntArray(int n) {
            int a[] = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

        public String readString() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = snext();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public String nextLine() {
            int c = snext();
            while (isSpaceChar(c))
                c = snext();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = snext();
            } while (!isEndOfLine(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;
        }

        private boolean isEndOfLine(int c) {
            return c == '\n' || c == '\r' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }

    }
    static 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();
		}
 
		}
    static int gcd(int a, int b) 
    { 
        if (a == 0) 
            return b; 
        return gcd(b % a, a); 
    } 
    static int mod = (int)(1e9+7);
    public static long pow(long a,long b)
    {
        long ans = 1;
        while(b> 0)
        {
            if((b & 1)==1){
                ans = (ans*a) % mod; 
            }
            a = (a*a) % mod;
            b = b>>1;
        }
        return ans;
    }
    static void sort(int[] a) {
		ArrayList<Integer> l=new ArrayList<>();
		for (int i:a) l.add(i);
		Collections.sort(l);
		for (int i=0; i<a.length; i++) a[i]=l.get(i);
    }
    static class Pair{
        char c;
        int count;
        public Pair(char c,int count)
        {
            this.c = c;
            this.count = count;
        }
    }
    static boolean solve(List<Pair> list1,List<Pair> list2,int idx,int k)
    {
        if(idx==list1.size())
            return true;
        Pair cur = list1.get(idx);
        // System.out.println(cur.c);
        if(cur.count==0)
        {
            return solve(list1,list2,idx+1,k);
        }
        // if(cur.count<k)
            // return false;
        for(Pair p:list2)
        {
            if(p.c==cur.c && p.count>0)
            {
                if(p.count>=cur.count)
                {
                    p.count-=cur.count;
                    if(solve(list1,list2,idx+1,k))
                        return true;
                    p.count+=cur.count;
                }
                // else{
                //     list1.get(idx).count-=p.count;
                //     if(solve(list1,list2,idx,k))
                //         return true;
                //     list1.get(idx).count+=p.count;
                // }
            }
            else if(p.c>cur.c && p.count>0)
            {
                if(p.count>=cur.count && cur.count%k==0)
                {
                    p.count-=cur.count;
                    if(solve(list1,list2,idx+1,k))
                        return true;
                    p.count+=cur.count;
                }
                // else if(p.count%k==0){
                //     list1.get(idx).count-=p.count;
                //     if(solve(list1,list2,idx,k))
                //         return true;
                //     list1.get(idx).count+=p.count;
                // }
            }
        }
        return false;
    }
    public static void main(String[] args) {
        InputReader in = new InputReader(System.in);
        OutputWriter out = new OutputWriter(System.out);
        int t = in.nextInt();
        while(t-- >0)
        {
            int n = in.nextInt(),k = in.nextInt();
            String a = in.nextLine();
            String b = in.nextLine();
            int[] counta = new int[26];
            int[] countb = new int[26];
            for(char c:a.toCharArray())
                counta[c-'a']++;
            for(char c:b.toCharArray())
                countb[c-'a']++;
            int[] countcur = new int[26];
            boolean flag = true;
            for(int i=0;i<26;i++)
            {
                countcur[i]+=counta[i];
                if(countcur[i]<countb[i])
                {
                    flag = false;
                    break;
                }
                countcur[i]-=countb[i];
                for(int j=0;j<=Math.min(i,25);j++)
                {
                    if(countcur[j]>=k)
                    {
                        int left = countcur[j]%k;
                        int toAdd = countcur[j]-left;
                        countcur[j]-=toAdd;
                        countcur[j+1]+=toAdd;
                    }
                }
            }
            if(flag)
            {
                out.printLine("Yes");
            }
            else
                out.printLine("No");
        }
        out.flush();
        out.close();
    }
}