#include<bits/stdc++.h>

using namespace std;

#define fastio ios_base::sync_with_stdio(0), cin.tie(NULL), cout.tie(NULL);

int main(){

fastio;

string vika = "vika";

int t;

cin>>t;

while(t--){

int n, m;

bool flag=false;

cin>>n>>m;

vector<string> str(n);

for(int i = 0; i < n; i++){

cin>>str[i];

}

int idx = 0;

for(int i = 0; i < m; i++){

bool check = false;

for(int j = 0; j < n; j++){

if(vika[idx] == str[j][i]){

check = true;

}

}

if(check){

idx++;

if(idx == 4){

break;

}

}

}

if(idx == 4){

cout<<"YES\n";

}else{

cout<<"NO\n";

}

}

return 0;

}