//********************************
//*????????????   **
//*?????? 1200012988 **
//*???2012.11.19  **
//********************************


int smaller(int, int);

int main()
{
    int n, a[101][101], i, j, k, min, count;
    cin >> n;
    count = n;                           //?count??n??
    for(k = 1; k <= count; k++)
    {
        int sum = 0;
        for(i = 0; i < n; i++)
        {
            for(j = 0; j < n; j++)
                cin >> a[i][j];
        }
        while(n > 1)
        {
            for(i = 0; i < n; i++)
            {
                min = a[i][0];
                for(j = 0; j < n; j++)
                {
                    if(min >= a[i][j])
                        min = a[i][j];     //????????
                }
                for(j = 0; j < n; j++)
                    a[i][j] -= min;        //?????????????
            }
            for(j = 0; j < n; j++)
            {
                min = a[0][j];
                for(i = 0; i < n; i++)
                {
                    if(min >= a[i][j])
                        min = a[i][j];     //????????
                }
                for(i = 0; i < n; i++)
                    a[i][j] -= min;        //?????????????
            }
            sum += a[1][1];                //sum??????????a[1][1]
            for(i = 0; i < n; i++)
            {
                for(j = 1 ;j < n - 1; j++)
                    a[i][j] = a[i][j + 1];
            }
            for(j = 0; j < n - 1; j++)
            {
                for(i = 1; i < n - 1; i++)
                    a[i][j] = a[i + 1][j];
            }                              //??
            n--;
        }
        cout << sum <<endl;                //????????a[1][1]??
        n = count;                         //??n??
    }

    return 0;
}
