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

int main() {
    int n;
    cin >> n;
    vector<vector<int> > dist(n, vector<int>(n));
    for (auto& row : dist){
        for (auto& d : row){
            cin >> d;
        }
    }
    vector<bool> connected(n, false);
    connected[0] = true;
    int total = 0;
    for (int k = 1; k < n; k++) {
        int min_d = INT_MAX, next = -1;
        for (int i = 0; i < n; i++) {
            if (connected[i]) {
                for (int j = 0; j < n; j++) {
                    if (!connected[j] && dist[i][j] < min_d) {
                        min_d = dist[i][j];
                        next = j;
                    }
                }
            }
        }
        connected[next] = true;
        total += min_d;
    }
    cout << total << endl;
    return 0;
}