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 javax.naming.InitialContext;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.math.*;
import java.text.DecimalFormat;
import java.lang.reflect.Array;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.util.concurrent.Phaser;

public class A {
    public static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
    static int MOD = (int) (1e9 + 7);
    //static int MOD = 998244353;
    static long MOD2 = MOD * MOD;
    static FastReader sc = new FastReader();
    static int pInf = Integer.MAX_VALUE;
    static int nInf = Integer.MIN_VALUE;
    public static void main(String[] args) {
        int test = 1;
        test = sc.nextInt();
        while (test-- > 0) solve();
        out.flush();
        out.close();
    }
    public static void solve() {
        int n = sc.nextInt();
        int k = sc.nextInt();
        char[] a = sc.next().toCharArray();
        char[] b = sc.next().toCharArray();
        Arrays.sort(a);
        Arrays.sort(b);
        int[] ca = new int[26];
        for(int i = 0; i < n; i++){
            ca[a[i]-'a']++;
        }
        StringBuffer sb = new StringBuffer();
        for(int i = 0; i < n; i++){
            int f = (int)(b[i]-'a');
            if(ca[f]>0){
                ca[f]--;
            }
            else{
                sb.append(b[i]);
            }
        }
        StringBuffer sa = new StringBuffer();
        for(int i = 0; i < 26; i++){
            for(int j = 0; j < ca[i]; j++){
                sa.append((char)(i+'a'));
            }
        }
        a = sa.toString().toCharArray();
        b = sb.toString().toCharArray();
        n = a.length;
//        out.println(a);
//        out.println(b);
        boolean ans = false;
        for(int i = 0; i < n; i++){
            if(a[i]==b[i]){
                continue;
            }
            else{
                char t1 = a[i];
                char t2 = b[i];
                int count = 0;
                while(i<n && a[i]==t1&&b[i]==t2){
                    i++;
                    count++;
                }
                if((count)%k==0&&t2>t1){
                    //out.println(count);
                }
                else{
                    ans = true;
                }
                i--;
            }
        }
        if(ans){
            out.println("No");
        }
        else{
            out.println("Yes");
        }
    }
    private static int[] zValues(char[] s) {
        int n=s.length;
        int[] z=new int[n];
        z[0]=s.length;
        int l=0, r=0;
        for (int i=1; i<n; i++) {
            if (i>r) {
                l=r=i;
                while (r<n&&s[r]==s[r-i])
                    r++;

                z[i]=r-l;
                r--;
            }
            else {
                int k=i-l;
                if (z[k]<r-i+1) {
                    z[i]=z[k];
                }
                else {
                    l=i;
                    while (r<n&&s[r-l]==s[r])
                        r++;
                    z[i]=r-l;
                    r--;
                }
            }
        }
        return z;
    }

    static class Node {
        ArrayList<Node> connect = new ArrayList<>();
        int comp = -1;

        public int gsize() {
            return connect.size();
        }
    }

//    static long nC2(long n) {
//        return add((n * (n + 1)) / 2, 0);
//    }
    public static int lowerBound(int key, int[] a) {
        int s = 0;
        int e = a.length - 1;
        if (e == -1) {
            return 0;
        }
        int ans = -1;
        while (s <= e) {
            int m = s + (e - s) / 2;
            if (a[m] >= key) {
                ans = m;
                e = m - 1;
            } else {
                s = m + 1;
            }
        }
        return ans == -1 ? s : ans;
    }

    public static int upperBound(int key, int[] a) {
        int s = 0;
        int e = a.length - 1;
        if (e == -1) {
            return 0;
        }
        int ans = -1;
        while (s <= e) {
            int m = s + (e - s) / 2;
            if (a[m] > key) {
                ans = m;
                e = m - 1;
            } else {
                s = m + 1;
            }
        }
        return ans == -1 ? s : ans;
    }

    public static long c2(long n) {
        if ((n & 1) == 0) {
            return mul(n / 2, n - 1);
        } else {
            return mul(n, (n - 1) / 2);
        }
    }

    public static long mul(long a, long b) {
        return ((a % MOD) * (b % MOD)) % MOD;
    }

    public static int add(int a, int b) {
        return ((a % MOD) + (b % MOD)) % MOD;
    }

    public static long sub(long a, long b) {
        return ((a % MOD) - (b % MOD)) % MOD;
    }

    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Integer.lowestOneBit(i)   Equals k where k is the position of the first one in the binary
//Integer.highestOneBit(i)  Equals k where k is the position of the last one in the binary
//Integer.bitCount(i)       returns the number of one-bits
//Collections.sort(A,(p1,p2)->(int)(p2.x-p1.x)) To sort ArrayList in descending order wrt values of x.
//            Arrays.parallelSort(a,new Comparator<TPair>() {
//      		public int compare(TPair a,TPair b) {
//        			if(a.y==b.y) return a.x-b.x;
//        			return b.y-a.y;
//        		}
//        	});
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//PrimeFactors    
    public static ArrayList<Long> primeFactors(long n) {
        ArrayList<Long> arr = new ArrayList<>();
        if (n % 2 == 0)
            arr.add((long) 2);
        while (n % 2 == 0)
            n /= 2;
        for (long i = 3; i <= Math.sqrt(n); i += 2) {
            int flag = 0;
            while (n % i == 0) {
                n /= i;
                flag = 1;
            }
            if (flag == 1)
                arr.add(i);
        }
        if (n > 2)
            arr.add(n);
        return arr;
    }

    //Pair Class
    static class Pair implements Comparable<Pair> {
        int x;
        int y;

        public Pair(int x, int y) {
            this.x = x;
            this.y = y;
        }
        @Override
        public int compareTo(Pair o) {
            if (this.x == o.x) {
                return (this.y - o.y);
            }
            return this.x-o.x;
        }
    }

    static class TPair implements Comparable<TPair> {
        int l;
        int r;
        int val;

        public TPair(int l, int r, int index) {
            this.l = l;
            this.r = r;
            this.val = val;
        }

        @Override
        public int compareTo(TPair o) {
            if (this.l == o.l) {
                return (this.r - o.r);
            }
            return (this.l - o.l);
        }
    }

    //nCr
    static long[] facts, factInvs;

    static long exp(long base, long e) {
        if (e == 0) return 1;
        long half = exp(base, e / 2);
        if (e % 2 == 0) return mul(half, half);
        return mul(half, mul(half, base));
    }

    static long modInv(long x) {
        return exp(x, MOD - 2);
    }

    static void precomp() {
        facts = new long[1_000_000];
        factInvs = new long[1_000_000];
        factInvs[0] = facts[0] = 1;
        for (int i = 1; i < facts.length; i++)
            facts[i] = mul(facts[i - 1], i);
        factInvs[facts.length - 1] = modInv(facts[facts.length - 1]);
        for (int i = facts.length - 2; i >= 0; i--)
            factInvs[i] = mul(factInvs[i + 1], i + 1);
    }

    static long nCk(int n, int k) {
        return mul(facts[n], mul(factInvs[k], factInvs[n - k]));
    }

    //Kadane's Algorithm
    static long maxSubArraySum(ArrayList<Long> a) {
        if (a.size() == 0) {
            return 0;
        }
        long max_so_far = a.get(0);
        long curr_max = a.get(0);
        for (int i = 1; i < a.size(); i++) {
            curr_max = Math.max(a.get(i), curr_max + a.get(i));
            max_so_far = Math.max(max_so_far, curr_max);
        }
        return max_so_far;
    }

    //Shuffle Sort
    static final Random random = new Random();

    static void ruffleSort(int[] a) {
        int n = a.length;//shuffle, then sort
        for (int i = 0; i < n; i++) {
            int oi = random.nextInt(n), temp = a[oi];
            a[oi] = a[i];
            a[i] = temp;
        }
        Arrays.sort(a);
    }

    //Merge Sort
    static void merge(long arr[], int l, int m, int r) {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        long L[] = new long[n1];
        long R[] = new long[n2];

        /*Copy data to temp arrays*/
        for (int i = 0; i < n1; ++i)
            L[i] = arr[l + i];
        for (int j = 0; j < n2; ++j)
            R[j] = arr[m + 1 + j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2) {
            if (L[i] <= R[j]) {
                arr[k] = L[i];
                i++;
            } else {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1) {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2) {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    static void sort(long arr[], int l, int r) {
        if (l < r) {
            // Find the middle point
            int m = (l + r) / 2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr, m + 1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }

    //Brian Kernighans Algorithm
    static long countSetBits(long n) {
        if (n == 0) return 0;
        return 1 + countSetBits(n & (n - 1));
    }

    //Factorial
    static long factorial(long n) {
        if (n == 1) return 1;
        if (n == 2) return 2;
        if (n == 3) return 6;
        return n * factorial(n - 1);
    }

    //Euclidean Algorithm
    static long gcd(long A, long B) {
        if (B == 0) return A;
        return gcd(B, A % B);
    }

    //Modular Exponentiation
    static long fastExpo(long x, long n) {
        if (n == 0) return 1;
        if ((n & 1) == 0) return fastExpo((x * x) % MOD, n / 2) % MOD;
        return ((x % MOD) * fastExpo((x * x) % MOD, (n - 1) / 2)) % MOD;
    }

    //AKS Algorithm
    static boolean isPrime(long n) {
        if (n <= 1) return false;
        if (n <= 3) return true;
        if (n % 2 == 0 || n % 3 == 0) return false;
        for (int i = 5; i <= Math.sqrt(n); i += 6)
            if (n % i == 0 || n % (i + 2) == 0) return false;
        return true;
    }

    //Reverse an array
    static <T> void reverse(T arr[], int l, int r) {
        Collections.reverse(Arrays.asList(arr).subList(l, r));
    }

    //Print array
    static void print1d(long arr[]) {
        out.println(Arrays.toString(arr));
    }

    static void print2d(int arr[][]) {
        for (int a[] : arr) out.println(Arrays.toString(a));
    }

    //Sieve of eratosthenes
    static int[] findPrimes(int n) {
        boolean isPrime[] = new boolean[n + 1];
        ArrayList<Integer> a = new ArrayList<>();
        int result[];
        Arrays.fill(isPrime, true);
        isPrime[0] = false;
        isPrime[1] = false;
        for (int i = 2; i * i <= n; ++i) {
            if (isPrime[i] == true) {
                for (int j = i * i; j <= n; j += i) isPrime[j] = false;
            }
        }
        for (int i = 0; i <= n; i++) if (isPrime[i] == true) a.add(i);
        result = new int[a.size()];
        for (int i = 0; i < a.size(); i++) result[i] = a.get(i);
        return result;

    }

    //Indivisual factors of all nos till n
    static ArrayList<Integer>[] indiFactors(int n) {
        ArrayList<Integer>[] A = new ArrayList[n + 1];
        for (int i = 0; i <= n; i++) {
            A[i] = new ArrayList<>();
        }
        int[] sieve = new int[n + 1];
        for (int i = 2; i <= n; i++) {
            if (sieve[i] == 0) {
                for (int j = i; j <= n; j += i)
                    if (sieve[j] == 0) {
                        //sieve[j]=i;
                        A[j].add(i);
                    }
            }
        }
        return A;
    }

    //Segmented Sieve
    static boolean[] segmentedSieve(long l, long r) {
        boolean[] segSieve = new boolean[(int) (r - l + 1)];
        Arrays.fill(segSieve, true);
        int[] prePrimes = findPrimes((int) Math.sqrt(r));
        for (int p : prePrimes) {
            long low = (l / p) * p;
            if (low < l) {
                low += p;
            }
            if (low == p) {
                low += p;
            }
            for (long j = low; j <= r; j += p) {
                segSieve[(int) (j - l)] = false;
            }
        }
        if (l == 1) {
            segSieve[0] = false;
        }
        return segSieve;
    }

    //Euler Totent function
    static long countCoprimes(long n) {
        ArrayList<Long> prime_factors = new ArrayList<>();
        long x = n, flag = 0;
        while (x % 2 == 0) {
            if (flag == 0) prime_factors.add(2L);
            flag = 1;
            x /= 2;
        }
        for (long i = 3; i * i <= x; i += 2) {
            flag = 0;
            while (x % i == 0) {
                if (flag == 0) prime_factors.add(i);
                flag = 1;
                x /= i;
            }
        }
        if (x > 2) prime_factors.add(x);
        double ans = (double) n;
        for (Long p : prime_factors) {
            ans *= (1.0 - (Double) 1.0 / p);
        }
        return (long) ans;
    }

    static long modulo = (long) 1e9 + 7;

    public static long modinv(long x) {
        return modpow(x, modulo - 2);
    }

    public static long modpow(long a, long b) {
        if (b == 0) {
            return 1;
        }
        long x = modpow(a, b / 2);
        x = (x * x) % modulo;
        if (b % 2 == 1) {
            return (x * a) % modulo;
        }
        return x;
    }

    public static class FastReader {
        BufferedReader br;
        StringTokenizer st;
        //it reads the data about the specified point and divide the data about it ,it is quite fast
        //than using direct

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception r) {
                    r.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());//converts string to integer
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (Exception r) {
                r.printStackTrace();
            }
            return str;
        }
    }
}