#include<bits/stdc++.h>
using namespace std;
const int inf=0x7f7f7f7f;
int maxn=0x7f;
int n,m,f[105][105],minn[105],ans,index;
bool vis[10005];
void primlll(){
	for(int i=1;i<=n;i++){
		for(int k=1;k<=n;k++){
			if(minn[k]<maxn&&!vis[k]){
				index=k,maxn=minn[k];		
			}
		}
		maxn=0x7f;
		vis[index]=1;
		ans+=minn[index];
		for(int j=1;j<=n;j++){
			if(vis[j]!=1&&f[index][j]<minn[j]){
				minn[j]=f[index][j];
			}
		}
	}
}
int main(){
	cin>>n;
	int x,y,z;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cin>>f[i][j];
		}
	}
	memset(minn,0x7f,sizeof(minn));
	minn[1]=0;
	primlll();
	cout<<ans;
	return 0;
}