D

#include <bits/stdc++.h>
using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back

int main()
{
    _test
    {
        int n; cin >> n;

        int a[n + 2][n + 2];

        for (int i = 0; i <= n + 1; i++){
            for (int j = 0; j <= n + 1; j++) a[i][j] = 0;
        }

        for (int i = 1; i <= n; i++){
            for (int j = 1; j <= n; j++){
                char c; cin >> c;
                a[i][j] = c - '0';
            }
        }

        for (int i = n; i >= 1; i--){
            for (int j = 1; j <= n; j++) a[i][j] ^= a[i - 1][j];
        }

        int b[n + 1][n + 1];
        int c[n + 1][n + 1];
        for (int i = 0; i <= n; i++){
            for (int j = 0; j <= n; j++){
                b[i][j] = c[i][j] = 0;
            }
        }

        int ans = 0;
        for (int i = 1; i <= n; i++){
            for (int j = 1; j <= n; j++){
                if (b[i][j]){
                    a[i][j] ^= 1;
                    b[i + 1][j - 1] ^= 1;
                }
                if (c[i][j]){
                    a[i][j] ^= 1;
                    c[i + 1][j + 1] ^= 1;
                }
            }
            for (int j = 1; j <= n; j++){
                if (a[i][j]){
                    ans++;
                    b[i + 1][j - 1] ^= 1;
                    c[i + 1][j + 1] ^= 1;
                }
            }

        }

        cout << ans << endl;
    }
}