#define _CRT_SECURE_NO_WARNINGS

#pragma comment(linker, "/STACK:268435456")

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <vector>

using namespace std;

//const string IN_NAME = "input.txt";
//const string OUT_NAME = "output.txt";

const string NAME = "cube";
const string IN_NAME = NAME + ".in";
const string OUT_NAME = NAME + ".out";

template<class T> T abs(T &x)       { return ((x) >= 0) ? (x) : (-(x)); }
template<class T> T sqr(T &x)       { return (x) * (x); }
template<class T> T min(T &a, T &b) { return ((a) < (b)) ? (a) : (b); }
template<class T> T max(T &a, T &b) { return ((a) > (b)) ? (a) : (b); }

#define sz(v) ((int) ((v).size()))
#define all(v) (v).begin(), (v).end()
#define fori(i,n) for (int i = 0; i < (n); i++)
#define show(x) { cout << (#x) << " = " << (x) << endl; }

typedef long long ll;
typedef pair<int, int> ii;

//------------------------------------------------------------------------------

int n;
char a[20][20][20];
char b[20][20];
bool v[20][20][20];

/*
void rotate1() {
    for (int k = 0; k < n; k++) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                b[i][j] = a[n-1-j][i][k];
            }
        }
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                a[i][j][k] = b[i][j];
            }
        }
    }
}

void rotate2() {
    for (int j = 0; j < n; j++) {
        for (int i = 0; i < n; i++) {
            for (int k = 0; k < n; k++) {
                b[i][k] = a[n-1-k][j][i];
            }
        }
        for (int i = 0; i < n; i++) {
            for (int k = 0; k < n; k++) {
                a[i][j][k] = b[i][k];
            }
        }
    }
}

void rotate3() {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                b[j][k] = a[i][n-1-k][j];
            }
        }
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                a[i][j][k] = b[j][k];
            }
        }
    }
}
*/

bool good(int x, int y, int z) {
    return (x >= 0 && x < n) && (y >= 0 && y < n) && (z >= 0 && z < n);
}

const int dx[6] = {1,-1,0,0,0,0};
const int dy[6] = {0,0,1,-1,0,0};
const int dz[6] = {0,0,0,0,1,-1};

void dfs(int x, int y, int z) {
    v[x][y][z] = true;
    for (int k = 0; k < 6; k++) {
        int nx = x + dx[k];
        int ny = y + dy[k];
        int nz = z + dz[k];
        if (good(nx, ny, nz) && !v[nx][ny][nz] && a[nx][ny][nz] == a[x][y][z]) {
            dfs(nx, ny, nz);
        }
    }
}

bool tryMoveOutIJ0(int x, int y) {
    memset(v, 0, sizeof(v));
    dfs(x, y, 0);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 1; k < n; k++) {
                if (v[i][j][k]) {
                    if (a[i][j][k-1] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool tryMoveOutIJN(int x, int y) {
    memset(v, 0, sizeof(v));
    dfs(x, y, n-1);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = n-2; k >= 0; k--) {
                if (v[i][j][k]) {
                    if (a[i][j][k+1] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool tryMoveOutIK0(int x, int z) {
    memset(v, 0, sizeof(v));
    dfs(x, 0, z);
    for (int i = 0; i < n; i++) {
        for (int j = 1; j < n; j++) {
            for (int k = 0; k < n; k++) {
                if (v[i][j][k]) {
                    if (a[i][j-1][k] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool tryMoveOutIKN(int x, int z) {
    memset(v, 0, sizeof(v));
    dfs(x, n-1, z);
    for (int i = 0; i < n; i++) {
        for (int j = n-2; j >= 0; j--) {
            for (int k = 0; k < n; k++) {
                if (v[i][j][k]) {
                    if (a[i][j+1][k] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool tryMoveOutJK0(int y, int z) {
    memset(v, 0, sizeof(v));
    dfs(0, y, z);
    for (int i = 1; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                if (v[i][j][k]) {
                    if (a[i-1][j][k] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool tryMoveOutJKN(int y, int z) {
    memset(v, 0, sizeof(v));
    dfs(n-1, y, z);
    for (int i = n-2; i >= 0; i--) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                if (v[i][j][k]) {
                    if (a[i+1][j][k] != a[i][j][k]) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

bool solveTest() {
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (tryMoveOutIJ0(i, j))
                return true;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (tryMoveOutIJN(i, j))
                return true;
    for (int i = 0; i < n; i++)
        for (int k = 0; k < n; k++)
            if (tryMoveOutIK0(i, k))
                return true;
    for (int i = 0; i < n; i++)
        for (int k = 0; k < n; k++)
            if (tryMoveOutIKN(i, k))
                return true;
    for (int j = 0; j < n; j++)
        for (int k = 0; k < n; k++)
            if (tryMoveOutJK0(j, k))
                return true;
    for (int j = 0; j < n; j++)
        for (int k = 0; k < n; k++)
            if (tryMoveOutJKN(j, k))
                return true;
    return false;
}

int main()
{
#ifndef ONLINE_JUDGE
    freopen(IN_NAME.c_str(), "r", stdin);
    freopen(OUT_NAME.c_str(), "w", stdout);
#endif

    int tests;
    cin >> tests;
    for (int t = 1; t <= tests; t++) {
        cin >> n;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                string s;
                cin >> s;
                for (int k = 0; k < n; k++) {
                    a[i][j][k] = s[k];
                }
            }
        }
        if (n > 1 && solveTest()) {
            cout << "No" << endl;
        } else {
            cout << "Yes" << endl;
        }
    }
}