package com.company;

import java.io.BufferedInputStream;
import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(new BufferedInputStream(System.in));
        while (sc.hasNext()) {
            int N = sc.nextInt();
            int[][] cost = new int[N][N];
            int[] d = new int[N];
            boolean[] used = new boolean[N];
            final int INF = Integer.MAX_VALUE/3;
            for (int i = 0; i < cost.length; i++) {
                d[i] = INF;
                for (int j = 0; j < cost.length; j++) {
                    cost[i][j] = sc.nextInt();
                }
            }
            d[0] = 0;
            //prim
            {
                PriorityQueue<Node>  pq = new PriorityQueue<Node>(100, new Comparator<Node>() {
                    @Override
                    public int compare(Node o1, Node o2) {
                        return o1.dis - o2.dis;
                    }
                });
                Node n = new Node(0, 0);
                pq.add(n);
                int res = 0;
                while (!pq.isEmpty()) {
                    Node tn = pq.poll();
                    if (d[tn.id] < tn.dis) continue;
                    if (used[tn.id]) continue;
                    res += tn.dis;
                    used[tn.id] = true;
                    for (int i = 0; i < N; i++) {
                        if (i == tn.id) continue;
                        if (d[i] > cost[tn.id][i]) {
                            d[i] = cost[tn.id][i];
                            n = new Node(d[i], i);
                            pq.add(n);
                        }
                    }
                }
                System.out.println(res);
            }
        }
    }
}
class Node {
    int dis, id;
    Node (int a, int b) {
        this.dis = a;
        this.id = b;
    }
}