#include<iostream>
#include<algorithm>
#include<cstring>
#include <queue>
#define x first
#define y second
using namespace std;
typedef pair<int, int> PII;
const int N=310;
int n,k;
int w[N][N];
bool st[N];
int prim(int res = 0)
{
    priority_queue<PII,vector<PII>,greater<PII>>heap;
    heap.push({0,0});
    while(heap.size())
    {
        auto [d , u] = heap.top();
        heap.pop();
        if(st[u]) continue;
        st[u] = true;
        res += d;
        for(int i=1;i<=n;i++) heap.push({w[u][i],i});
    }
    return res;
}
int main()
{
    cin >> n;
    for(int i=0;i<=n;i++)
        for(int j=1;j<=n;j++)
            cin >> w[i][j];
    cout << prim() << endl;
    return 0;
}