#include<cstdio>
#include<iostream>
#include<cstring>//Prim算法 
#define N 110
using namespace std;
int g[N][N],minn[N],vis[N],n;
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            scanf("%d",&g[i][j]);
        }
    }
    memset(minn,0x7f,sizeof minn);
    minn[1]=0;
    for(int i=1;i<=n;i++){
        int k=0;
        for(int j=1;j<=n;j++){
            if(!vis[j]&&(minn[j]<minn[k])){
                k=j;
            }
        }
        vis[k]=1;
        for(int j=1;j<=n;j++){
            if(!vis[j]&&(g[k][j]<minn[j])){
                minn[j]=g[k][j];
            }
        }
    }
    int tot=0;
    for(int i=1;i<=n;i++){
        tot+=minn[i];
    }
    printf("%d\n",tot);
    return 0;
}