#include <bits/stdc++.h> #define ll long long #define ld long double #define mod 1000000007 using namespace std; #define pb push_back #define mp make_pair #define f first #define s second #define all(arr) arr.begin() , arr.end() #define FAST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL) #define rep(i , a , n) for(int i = a ; i < n ; i++) #define ms(arr , val) memset(arr , 0 , sizeof(arr)) #define siz(temp) temp.size() #define len(temp) temp.length() #define timepass 1073741824 ll modexpo(ll a , ll b) { ll res = 1; while(b > 0) { if(b&1) res = (res*a)%mod; a=(a*a)%mod; b >>=1; } return res; } ll expo(ll a , ll b) { ll res = 1; while(b > 0) { if(b&1) res = (res*a); a=(a*a); b >>=1; } return res; } ll gcd(ll a , ll b) { if (a == 0) return b; return gcd(b%a , a); } bool isPrime(ll n) { if (n <= 1) return false; if (n <= 3) return true; if (n%2 == 0 || n%3 == 0) return false; for (int i = 5 ; i*i <= n ; i+=6) { if ((n%i==0) || (n%(i + 2) == 0)) return false; } return true; } ll nCr(ll n , ll r) { if(r == 0) return 1; return (n*nCr(n - 1 , r - 1))/r; } int main() { int t; cin >> t; while(t--) { int n; cin >> n; int arr[n][n]; rep(i , 0 , n) rep(j , 0 , n) cin >> arr[i][j]; int t = arr[0][0]; int f = 0; for (int i = 0 ; i < n ; i++) { for (int j = 0 ; j < n ; j++) { if ((i+j)%2 == 0 && arr[i][j] != t) { cout << "No\n"; f = 1; break; } else if ((i+j)%2 == 1 && arr[i][j] == t) { cout << "No\n"; f = 1; break; } } if (f == 1) break; } if (f == 0) cout << "Yes\n"; } return 0; }