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.io.*;
    import java.util.*;
    import static java.lang.System.*;
    import static java.lang.Math.*;
    import static java.util.Collections.*;
    import static java.util.Arrays.*;
    public class Main<Array, Target> {
        public static int swap(int... args) {
            return args[0];
        }
      //  static Scanner sc = new Scanner(System.in);
         static FastReader sc = new FastReader();
        public static void main(String[] args) throws IOException {
            do {
                startTime = currentTimeMillis();
                //setOut(new PrintStream("output"));
                //setIn(new FileInputStream("input"));
                int T = sc.nextInt();while (T-- != 0)
                {
                    solve();

                }
                endTime = currentTimeMillis();
                long duration = endTime - startTime;
                //out.println(duration);
                if (false) {
                    out.println(max(3, 2));
                    Integer[] ARRAY = new Integer[2];
                    ArrayList<Integer> LIST = new ArrayList<>();
                    LIST.add(2);
                    // sort(LIST, reverseOrder());
                    LIST.sort(reverseOrder());
                    sort(ARRAY, reverseOrder());
                    out.println(LIST + " " + Arrays.toString(ARRAY));
                }
            } while (LOCAL);
        }
        public static boolean isPal(String s)
        {
            StringBuilder stringBuilder = new StringBuilder(s);
            return s.equals(stringBuilder.reverse().toString());
        }
        public static void solve() throws IOException {
            Main main = new Main<>();
    /////////////////////////////////////////////////////////////////////

            int n = sc.nextInt();
            int k = sc.nextInt();
         //   sc.nextLine();
            String a = sc.nextLine();
            String b = sc.nextLine();
            int[] have = new int[27];
            int[] need = new int[27];
            for(int i = 0; i < n; i++)
            {
                have[a.charAt(i) - 'a']++;
                need[b.charAt(i) - 'a']++;
            }
            boolean bad = false;
            for(int j = 25; j >= 0; j--){
                have[j] += have[j + 1];
                need[j] += need[j + 1];
                if(have[j] > need[j] || (need[j] - have[j]) % k != 0) {
                    bad = true;
                    break;
                }
            }
            if(bad)
                System.out.println("No");
            else
                System.out.println("Yes");

    ///////////////////////////////////////////////////////////////////////
        }
        public static final boolean LOCAL = System.getProperty("ONLINE_JUDGE")==null;
        // public static final boolean LOCAL = System.getProperty("LOCAL")!=null;
        public static final String ANSI_RED = "\u001B[31m";
        public static final String ANSI_RESET = "\u001B[0m";
        static long startTime;
        static long endTime;
        static boolean[] prime;
        static final int M = (int) 1e9 + 7;
        static final long MM = (long) M * M;
        static final int MAX = Integer.MAX_VALUE;
        static final int MIN = Integer.MIN_VALUE;
        static final int SIZE = (int) 1e9 * 2;
        static class FastReader {
            BufferedReader br;
            StringTokenizer st;
            public FastReader() {
                br = new BufferedReader(new
                        InputStreamReader(System.in));
            }
            String next() {
                while (st == null || !st.hasMoreElements()) {
                    try {
                        st = new StringTokenizer(br.readLine());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                return st.nextToken();
            }
            int nextInt() {
                return Integer.parseInt(next());
            }
            long nextLong() {
                return Long.parseLong(next());
            }
            double nextDouble() {
                return Double.parseDouble(next());
            }
            String nextLine() {
                String str = "";
                try {
                    str = br.readLine();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return str;
            }
        }
        static class Pair implements Comparable<Pair> {
            private int key;
            private int value;
            public Pair(int key, int value) {
                this.key = key;
                this.value = value;
            }
            public int second() {
                return value;
            }
            @Override
            public int compareTo(Pair o) {
                return -Integer.compare(key, o.key);
            }
            @Override
            public String toString() {
                return "Pair{" + "x=" + key + ", y=" + value + '}';
            }
        }
        int count(Array[] array, Target target){
            int cn=0;
            for (Array value : array) {
                if (value.equals(target)) cn++;
            }
            return cn;
        }
        static int count (String string , char target){
            int cn=0;
            for (int i = 0; i < string.length(); i++) {
                if(string.charAt(i)==target)cn++;
            }
            return cn;
        }
        void revArray(Array [] arr) {
            int n = arr.length;
            for (int i = 0; i < n / 2; i++) {
                Array temp = arr[i];
                arr[i] = arr[n - i - 1];
                arr[n - i - 1] = temp;
            }
        }
        void printArray(Array [] arr) {
            int n = arr.length;
            for (Array array : arr)out.print(array + " ");
            out.println();
        }
        static void yes() {out.println("YES");}
        static void no() {out.println("NO");}
        public static int lowerBound(Integer[] array, int length, int value) {
            int low = -1;
            int hi = length;
            while (low + 1 < hi) {
                int mid = (low + hi) / 2;
                if (array[mid] <= value) {
                    low = mid;
                } else {
                    hi = mid;
                }
            }
            return low;
        }
        public static int upperBound(Integer[] array, int length, int value) {
            int low = -1;
            int hi = length;
            while (low + 1 < hi) {
                int mid = (low + hi) >> 1;
                if (array[mid] >= value) {
                    hi = mid;
                } else low = mid;
            }
            return hi;
        }
        public static int binarySearch(Integer[] arr, int length, int value) {
            int low = 0;
            int hi = length - 1;
            int ans = -1;
            while (low <= hi) {
                int mid = (low + hi) >> 1;
                if (arr[mid] > value) {
                    hi = mid - 1;
                } else if (arr[mid] < value) {
                    low = mid + 1;
                } else {
                    ans = mid;
                    break;
                }
            }
            return ans;
        }
        public static int gcd(int a, int b) {
            return b==0?a:gcd(b, a % b);
        }
        public static long lcm(int a, int b) {
            return a / gcd(a, b) * b;
        }
        public static int countDivs(int n) {
            int cn = 0;
            int sqr = (int) Math.sqrt(n);
            for (int i = 1; i <= sqr; ++i) {
                if (n % i == 0) {
                    ++cn;
                }
            }
            cn *= 2;
            if (sqr * sqr == n) cn--;
            return cn;
        }

        static void prime(int x) {
    //sieve algorithm. nlog(log(n)).
            prime = new boolean[(x + 1)];
            Arrays.fill(prime, true);
            prime[0] = prime[1] = false;
            for (int i = 2; i * i <= x; i++)
                if (prime[i])
                    for (int j = i * i; j <= x; j += i)
                        prime[j] = false;
        }
        static boolean isEven(long x) {
            return x % 2 == 0;
        }
        static boolean isPrime(long x) {
            boolean flag = true;
            int sqr = (int) Math.sqrt(x);
            if (x < 2) return false;
            for (int i = 2; i <= sqr; i++) {
                if (x % i == 0) {
                    flag = false;
                    break;
                }
            }
            return flag;
        }

        static long factorial(long x) {
            long total = 1;
            for (int i = 2; i <= x; i++)
                total = (total * i) % M;
            return total;
        }

        static long power(long x, long n) {
            if (n == 0) {
                return 1;
            }
            long pow = power(x, n / 2L);
            if ((n & 1) == 1) {
                return (x * (pow) * (pow));
            }
            return (pow * pow);
        }
        private static <T> String ts(T t) {
            if(t==null) {
                return "null";
            }
            try {
                return ts((Iterable) t);
            }catch(ClassCastException e) {
                if(t instanceof int[]) {
                    String s = Arrays.toString((int[]) t);
                    return "{"+s.substring(1, s.length()-1)+"}";
                }else if(t instanceof long[]) {
                    String s = Arrays.toString((long[]) t);
                    return "{"+s.substring(1, s.length()-1)+"}";
                }else if(t instanceof char[]) {
                    String s = Arrays.toString((char[]) t);
                    return "{"+s.substring(1, s.length()-1)+"}";
                }else if(t instanceof double[]) {
                    String s = Arrays.toString((double[]) t);
                    return "{"+s.substring(1, s.length()-1)+"}";
                }else if(t instanceof boolean[]) {
                    String s = Arrays.toString((boolean[]) t);
                    return "{"+s.substring(1, s.length()-1)+"}";
                }
                try {
                    return ts((Object[]) t);
                }catch(ClassCastException e1) {
                    return t.toString();
                }
            }
        }
        private static <T> String ts(T[] arr) {
            StringBuilder ret = new StringBuilder();
            ret.append("{");
            boolean first = true;
            for(T t: arr) {
                if(!first) {
                    ret.append(", ");
                }
                first = false;
                ret.append(ts(t));
            }
            ret.append("}");
            return ret.toString();
        }
        private static <T> String ts(Iterable<T> iter) {
            StringBuilder ret = new StringBuilder();
            ret.append("{");
            boolean first = true;
            for(T t: iter) {
                if(!first) {
                    ret.append(", ");
                }
                first = false;
                ret.append(ts(t));
            }
            ret.append("}");
            return ret.toString();
        }
        public static void dbg(Object... o) {
            if(LOCAL) {
                System.err.print("Line #"+Thread.currentThread().getStackTrace()[2].getLineNumber()+": [");
                for(int i = 0; i<o.length; i++) {
                    if(i!=0) {
                        System.err.print(", ");
                    }
                    System.err.print(ts(o[i]));
                }
                System.err.println("]");
            }
        }

    }