#include <bits/stdc++.h> using namespace std ; #define inf 0x3f3f3f3f #define INF 1000111000111000111LL #define mod 1000000007 #define pi acos(-1.0) #define eps 1e-8 #define endl '\n' #define mp make_pair #define mt make_tuple #define pb push_back #define fi first #define se second #define all(cc) (cc).begin(),(cc).end() using lli = long long int ; using pii = pair<int, int> ; using vi = vector<int> ; using vb = vector<bool> ; using vvi = vector<vector<int>> ; using vlli = vector<long long int> ; using vpii = vector<pair<int, int>> ; int main() { ios_base::sync_with_stdio (false) ; cin.tie(0) ; cout.tie(0) ; int T ; cin>> T ; while(T--) { int n, grid[105][105] ; bool pos=true ; cin>> n ; for(int i=1 ; i<=n ; i++) for(int j=1 ; j<=n ; j++) cin>> grid[i][j] ; for(int i=1 ; i<=n ; i++) for(int j=1 ; j<=n ; j++) { if(i-1>=1 && grid[i-1][j]==grid[i][j]) pos=false ; if(j-1>=1 && grid[i][j-1]==grid[i][j]) pos=false ; if(i+1<=n && grid[i+1][j]==grid[i][j]) pos=false ; if(j+1<=n && grid[i][j+1]==grid[i][j]) pos=false ; } if(pos) cout<< "Yes" << endl ; else cout<< "No" << endl ; } }