#include <bits/stdc++.h>
using namespace std;
 
 void init_code(){
	#ifndef ONLINE_JUDGE
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	#endif
}
 

 
int main() {
  init_code();
  // read(T);
	int T;
	cin>>T;
  while(T > 0){
  	int n,ans = 0;
  	cin>>n;
  	vector<string>v(n);
  	for(auto&i:v){
  		cin>>i;
  	}
  	vector<vector<int>>left(n,vector<int>(n)), right(n,vector<int>(n)), down(n, vector<int>(n));
  	for(int i = 0;i<n;i++){
  		for(int j = 0;j<n;j++){
  			int x = v[i][j] - '0';
  			if(left[i][j]){
  				x^=1;
  				if(i + 1 < n){
  					if(j - 1>=0){
  						left[i + 1][j - 1]^=1;
  					}
  					down[i + 1][j]^=1;

  				}
  			}
  			if(down[i][j]){
  				x^=1;
  				if(i + 1 <n){
  					down[i + 1][j]^=1;
  				}
  			}
  			if(right[i][j]){
  				x^=1;
  				if(i + 1 < n){
  					if(j + 1 < n){
  						right[i + 1][j + 1]^=1;
  					}
  					down[i + 1][j]^=1;
  				}
  			}

  			if(x){
  				ans++;
  				if(i + 1 < n){
  					if(j - 1 >= 0){
  						left[i + 1][j - 1]^=1;
  					}
  					if(j + 1<n){
  						right[i + 1][j + 1]^=1;
  					}
  					down[i + 1][j]^=1;
  				}

  			}

  		}

  	}
 	cout<<ans<<endl;
 	T--;
  }
}

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int mod = 998244353;
template <typename T>
istream &operator>>(istream &istream, vector<T> &v){for (auto &it : v) cin >> it; return istream;}
template <typename T>
ostream &operator<<(ostream &ostream, vector<T> &v){for (auto &it : v) cout << it << ' '; return ostream;}
 
void solveIt(){
    int n; cin >> n;
    vector<string> a(n);
    for(auto &i : a) cin >> i;
    vector<vector<int>> left(n,vector<int> (n,0)),right(n,vector<int> (n,0)),down(n,vector<int> (n,0));
    int ans = 0;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            int x = a[i][j] - '0';
            if(left[i][j]){
                x ^= 1;
                if(i + 1 < n){
                    if(j - 1 >= 0) left[i + 1][j - 1] ^= 1;
                    down[i + 1][j] ^= 1;
                }
            }
            if(down[i][j]){
                x ^= 1;
                if(i + 1 < n) down[i + 1][j] ^= 1;
            }
            if(right[i][j]){
                x ^= 1;
                if(i + 1 < n){
                    if(j + 1 < n) right[i + 1][j + 1] ^= 1;
                    down[i + 1][j] ^= 1;
                }
            }
            if(x){
                ans++;
                if(i + 1 < n){
                    if(j - 1 >= 0) left[i + 1][j - 1] ^= 1;
                    down[i + 1][j] ^= 1;
                    if(j + 1 < n) right[i + 1][j + 1] ^= 1;
                }
            }
        }
    }
    cout << ans << '\n';
}
 
#undef int
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int tcs=1;
    cin >> tcs;
    for(int i=1;i<=tcs;i++){
        solveIt();
    }
}