import java.io.*;
import java.util.*;

public class Main{
    public static final int N=110;
    public static final int INF=(1<<30);
    public static boolean []vis=new boolean[N];
    public static int [][]edge=new int[N][N];
    public static int []low=new int [N];
    public static int sum;

    static int min(int a,int b){
        return a<b?a:b;
    }

    static void prim(int n){
        sum=0;
        Arrays.fill(vis,false);
        vis[1]=true;
        for(int i=1;i<=n;i++){
            low[i]=edge[1][i];
        }
        for(int i=1;i<n;i++){
            int Minlow=INF,idx=-1;
            for(int j=1;j<=n;j++){
                if(!vis[j]&&low[j]<Minlow){
                    Minlow=low[j];
                    idx=j;
                }
            }
            vis[idx]=true;
            sum+=Minlow;
            for(int j=1;j<=n;j++){
                if(!vis[j]){
                    low[j]=min(low[j],edge[idx][j]);
                }
            }
        }
    }
    public static void main(String []args){
        Scanner cin=new Scanner(System.in);
        while(cin.hasNext()){
            int n=cin.nextInt();
            for(int i=1;i<=n;i++){
                for(int j=1;j<=n;j++){
                    edge[i][j]=cin.nextInt();
                }
            }
            prim(n);
            System.out.println(sum);
        }
    }
}