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 PYTHON3):

Solution:
# Author Name: Ajay Meena
# Codeforce : https://codeforces.com/profile/majay1638

# import inbuilt standard input output
import sys
import math
from sys import stdin, stdout

# //Most Frequently Used Number Theory Concepts


def sieve(N):
    primeNumbers = [True]*(N+1)
    primeNumbers[0] = False
    primeNumbers[1] = False
    i = 2
    while i*i <= N:
        j = i
        if primeNumbers[j]:
            while j*i <= N:
                primeNumbers[j*i] = False
                j += 1
        i += 1
    return primeNumbers


def getPrime(N):
    primes = sieve(N)
    result = []
    for i in range(len(primes)):
        if primes[i]:
            result.append(i)
    return result


def factor(N):
    factors = []
    i = 1
    while i*i <= N:
        if N % i == 0:
            factors.append(i)
            if i != N//i:
                factors.append(N//i)
        i += 1
    return sorted(factors)


def gcd(a, b):
    if a < b:
        return gcd(b, a)
    if b == 0:
        return a
    return gcd(b, a % b)


def extendedGcd(a, b):
    if a < b:
        return extendedGcd(b, a)
    if b == 0:
        return [a, 1, 0]
    res = extendedGcd(b, a % b)
    x = res[2]
    y = res[1]-(math.floor(a/b)*res[2])
    res[1] = x
    res[2] = y
    return res


def iterativeModularFunc(a, b, c):
    res = 1
    while b > 0:
        if b & 1:
            res = (res*a) % c
        a = (a*a) % c
        b = b//2
    return res

# // Taking Input Format Helper Function


def get_ints_in_variables():
    return map(int, sys.stdin.readline().strip().split())


def get_int(): return int(input())


def get_ints_in_list(): return list(
    map(int, sys.stdin.readline().strip().split()))


def get_list_of_list(n): return [list(
    map(int, sys.stdin.readline().strip().split())) for _ in range(n)]


def get_string(): return sys.stdin.readline().strip()


def Solution(a, b, n, k):
    a1 = [0 for _ in range(26)]
    b1 = [0 for _ in range(26)]
    flag = False
    for c in a:
        a1[ord(c)-ord("a")] += 1
    for c in b:
        b1[ord(c)-ord("a")] += 1
    for i in range(26):
        if a1[i] < b1[i]:
            flag = True
        else:
            d = a1[i]-b1[i]
            if (d % k != 0):
                flag = True
            else:
                a1[(i+1) % 26] += d
    if flag:
        print("NO")
    else:
        print("YES")


def main():
    # //Write Your Code Here
    for _ in range(get_int()):
        n, k = get_ints_in_variables()
        a = get_string()
        b = get_string()
        Solution(a, b, n, k)


#  calling main Function
if __name__ == "__main__":
    main()