import java.util.*;
public class si2 {
public static void main(String[] args) {
int t;
Scanner sc = new Scanner(System.in);
t = sc.nextInt();
for (int i = 0; i < t; i++) {
int n = sc.nextInt();
int m = sc.nextInt();
char[][] carpetMat = new char[n][m];
for (int j = 0; j < n; j++) {
String line = sc.next();
for (int k = 0; k < m; k++) {
carpetMat[j][k] = line.charAt(k);
}
}
// for (int j = 0; j < n; j++) {
// for (int k = 0; k < m; k++) {
// System.out.print(carpetMat[j][k] + " ");
// }
// System.out.println();
// }
char words[] = {'v','i','k','a'};
int p = 0,vikaCount = 0;
for(int j = 0;j < m;j++){
for(int k = 0;k < n;k++){
if(carpetMat[k][j] == words[p]){
vikaCount++;
p++;
break;
}
}
}
if(vikaCount == 4){
System.out.println("Yes");
}
else{
System.out.println("No");
}
}
}
}