#include<bits/stdc++.h>
#define ll long long
using namespace std;
void solve(){
ll n, m;
cin >> n >> m;
vector<string> c(n);
for (int j = 0; j < n; j++){
cin >> c[j];
}
int p = 0;
for (int j = 0; j < m; j++){
bool ok = false;
for (int k = 0; k < n; k++){
if (c[k][j] == "vika"[p]){
ok = true;
}
}
if (ok){
p++;
if (p == 4){
break;
}
}
}
if (p == 4){
cout << "YES" << endl;
} else {
cout << "NO" << endl;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
freopen("error.txt", "w", stderr);
#endif
int t;
cin>>t;
while(t-- >0)
{
solve();
}
return 0;
}
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