#include <fstream>
#define N 100
using namespace std;
ifstream f("cc.in");
ofstream g("cc.out");
int n,sum;
int dist[N][N];
bool chosen[N];
int main()
{
    f>>n;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j<= n; j++){
            f>>dist[i][j];
        }
    }
    for(int i = 1; i<=n; i++)
    {
        int Min = 999999999,ct = 0;
        for(int j = 1; j<= n; j++)
        {
            if(Min>=dist[i][j] && !chosen[j]){
                Min = dist[i][j];
                ct = j;
            }
        }
        sum+=Min;
        chosen[ct] = 1;
    }
    g<<sum;
    f.close();
    g.close();
    return 0;
}