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 CPP):

Solution:
/*****************************************************************\
IN THE NAME OF ALLAH, MOST GRACIOUS AND MOST MERCIFUL
|                                                                 |
|     Author     : Mahabub Rahman                                 |
|     Email      : mahabubrahman618@gmail.com                     |
|     University : Comilla University, Bangladesh                 |
|                  Department of Computer Science & Engineering   |
\*****************************************************************/


/*...................................Data_Types............................................*/
#include<bits/stdc++.h>

using namespace std;
#define FastIO ios::sync_with_stdio(false); cin.tie(0);cout.tie(0)
#define       ll                  long long int
#define       ull                  unsigned long long int
#define       veci                 vector<int>
#define       vecc                 vector<char>
#define       vecs                 vector<string>
#define       vecl                 vector<long long int>
#define       vecp                 vector<  pair<int,int> >
#define       mapstrint            map< string , int >
#define       mapstrstr            map< string , string >
#define       mapint               map< int, int >
#define       pb                   push_back
#define       newline cerr << endl
#define       pob                  pop_back
#define       mp                   make_pair
#define       pii                  pair<int, int>
#define       F                    first
#define       S                    second
#define       sc(x)                scanf("%d",&x)
#define       sc2(xx,zz)           scanf("%d %d",&xx,&zz)
#define       scl(x)               scanf("%lld",&x)
#define       scl2(xx,zz)          scanf("%lld %lld",&xx,&zz)
#define       pf                   printf
#define       min3(a,b,c)          min(a,b<c?b:c)
#define       max3(a,b,c)          max(a,b>c?b:c)
#define       all(v)               v.begin(), v.end()
///=============== Debugging ============================///
#define       debug(x) cerr << #x << " = " << x << endl
#define       debug2(x, y)             cerr << #x << ": " << x << " | " << #y << ": " << y << endl;
#define       debug3(x, y, z)          cerr << #x << ": " << x << " | " << #y << ": " << y << " | " << #z << ": " << z << endl;
#define       debug4(a, b, c, d)       cerr << #a << ": " << a << " | " << #b << ": " << b << " | " << #c << ": " << c << " | " << #d << ": " << d << endl;
//#define f(x) (64 - __builtin_clzll(x))
///============ CONSTANT ===============///
#define mx9   1000000007
#define mx7   10000007
#define mx6   2000006
#define mx5   200005
#define inf   1<<30                                           //infinity value
#define eps   1e-9
#define mod   mx9
///==============================TEMPLATES===============================///

long double PI = acosl(-1);
bool compare_int(int a, int b){return (a>b);} //This function is use for descending order.
bool compare_string (string a, string b){return a.size()<b.size();}
bool compare_pair(const pair<int,int> &a,
                    const pair<int,int> &b){if(a.second==b.second)return a.first<b.first; else return (a.second > b.second);}
bool cmp(pair<string ,int > x , pair<string ,int > y){return (x.S < y.S);}
///=====================Graph Moves================///
//const int fx[]= {+1,-1,+0,+0};
//const int fy[]= {+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move

///=====================Bitmask===================///
//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}

///========================================FUNCTION=========================================///
//bool check(int n){if(n==1) return false; for(int i=2; i*i<=n; i++){if(n%i==0) return false;} return true;}
//ll bigmod(ll a, ll b, ll m){if(b==0) return 1%m;ll x=bigmod(a, b/2, m);x=(x*x)%m;if(b%2==1)x=(x*a)%m;return x;}
//bool flag[mx5];veci prime;
//void sieve(){prime.pb(2);for(ll i=3; i*i<=mx5; i+=2){if(flag[i]) continue;for(ll j=i*i; j<=mx5; j+=i+i) flag[j]=true;}for(ll i=3; i<=mx5; i+=2) if(!flag[i]) prime.pb(i);}
//ll fact(ll n){if(n==0 or n==1)return 1; else return n*fact(n-1);}
void NA(){printf("NO\n");exit(0);}
void YA(){printf("YES\n");exit(0);}

///=================START_FROM_HERE=====================///

int32_t main()
{
    ///Don't see test case until get 7/8 times wrong submission..!!
    ///Try to make Corner, Even, Odd or Prime case..!!
    FastIO;
    int t, n, m;
    cin>> t;
    while(t--)
    {
        string s, ss;
        cin >> n >> m >> s >> ss;
        veci a(26), b(26);
        for(int i=0; i<n; i++)
        {
            a[s[i]-'a']++;
            b[ss[i]-'a']++;
        }
        bool ok = true;
        for(int i=0; i<26; i++)
        {
            if(a[i]==b[i]) continue;
            if(a[i]<b[i])
            {
                ok = false;
                break;
            }
            if((a[i]-b[i])%m>0)
            {
                ok = false;
                break;
            }
            a[i+1]+=a[i]-b[i];
        }
        ok==true ? cout << "Yes\n" : cout << "No\n";
    }

}
///Created: