#include <iostream> #include <cstdio> #include <cstdlib> #include <cstring> #include <algorithm> using namespace std; int a[110][110]; int main() { int T; scanf("%d",&T); for (; T--;) { int n; scanf("%d",&n); for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) scanf("%d",&a[i][j]); bool flag = 1; for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) { if (i != 1 && a[i][j] == a[i - 1][j]) flag = 0; if (j != 1 && a[i][j] == a[i][j - 1]) flag = 0; if (i != n && a[i][j] == a[i + 1][j]) flag = 0; if (j != n && a[i][j] == a[i][j + 1]) flag = 0; } if (flag) puts("Yes"); else puts("No"); } return 0; }