#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

string s[111];

int main() {
	int t;
	cin >> t;
	while (t--) {
		int n;
		cin >> n;
		for (int i = 0; i < n; i++) cin >> s[i], sort(s[i].begin(), s[i].end());
		bool flag = true;
		for (int i = 0; i < n; i++) for (int j = 0; j + 1 < n; j++) if (s[j][i] > s[j + 1][i]) flag = false;
		puts(flag ? "YES" : "NO");
	}
	return 0;
}

import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) throws IOException {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int t = Integer.parseInt(br.readLine());
        while(t-->0){
            int n = Integer.parseInt(br.readLine());
            String[]grid = new String[n];
            for(int i=0;i<n;i++)
                grid[i] = sort(br.readLine());
            
            boolean ok = true;
            
            for(int i=0;i<n;i++){
                for(int j=1;j<n;j++){
                    if(grid[j].charAt(i) < grid[j-1].charAt(i)){
                        ok = false;
                        break;
                    }
                }
            }
            System.out.println(ok?"YES":"NO");
            
        }
    }
    
    public static String sort(String s){
        char[] array = s.toCharArray();
        Arrays.sort(array);
        return new String(array);
    }
}
 

def checkLex(arr, n):
    for j in range(n-1):
        for k in range(n):
            if arr[j][k] > arr[j+1][k]:
                return False
    return True
    

t = int(input().strip())

for i in range(t):
    n = int(input().strip())
    line = []
    for j in range(n):
        x = list(input().strip())
        x.sort()
        line.append(x)
    
    if checkLex(line, n):
        print("YES")
    else:
        print("NO")

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    int num_testcases, number;
    char array[100][100];
    int i, j, k, l;
    char c, t;
    int match;
    
    scanf("%d", &num_testcases);
    
    for (i = 0; i < num_testcases; i++) {
        scanf("%d", &number);
        match = 1;
        for (j = 0; j < number; j++) { /* no of lines */
            while ((c = fgetc(stdin)) == '\n') continue;
            ungetc(c, stdin);
            for (k = 0; ((k < number) && ((c = fgetc(stdin)) != '\n')); k++) {
                for(l = k; l>0; l--) {
                    if (array[j][l-1] > c) {
                        array[j][l] = array[j][l-1];
                    } else {
                        break;
                    }
                }
                array[j][l] = c;
          //      printf("wrote %c into [%d][%d]\n", c, j, l);
            }
        }
        /*printf("Array read is:\n");
        for (l = 0; l < number; l++) {
            for (j = 0; j < number; j++) {
                printf("%c", array[l][j]);
            }
            printf("\n");
        }
        printf("\n");
        */
        for (l = 0; l < number-1; l++) {
            for (j = 0; j < number-1; j++) {
                if ((array[l][j] > array[l][j+1]) ||
                    (array[l][j] > array[l+1][j])) {
                    match = 0;
                    goto done;
                }
            }
        }
        /* Check last row and last column */
        for (k = 0; k < number-1; k++) {
            if (array[l][k] > array[l][k+1]) {
                match = 0;
                goto done;
            }
        }
        for (k = 0; k < number-1; k++) {
            if (array[k][j] > array[k+1][j]) {
                match = 0;
                goto done;
            }
        }
done:
        if (match) {
            printf("YES\n");
        } else {
            printf("NO\n");
        }
    }
    return 0;
}