#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int g[101][101]; //邻接矩阵
int minn[101]; //minn[i]存放蓝点i与白点相连的最小边权
bool u[101]; //u[i]=True，表示顶点i还未加入到生成树中
//u[i]=False，表示顶点i已加入到生成树中
int n,i,j;
int main()
{
freopen("wire.in","r",stdin);
freopen("wire.out","w",stdout);
cin >> n;
for (i = 1; i <= n; i++)
for (j = 1; j <= n; j++)
cin >> g[i][j];
memset(minn,0x7f,sizeof(minn)); //初始化为maxint
minn[1] = 0;
memset(u,1,sizeof(u)); //初始化为True，表示所有顶点为蓝点
for (i = 1; i <= n; i++)
{
int k = 0;
for (j = 1; j <= n; j++) //找一个与白点相连的权值最小的蓝点k
if (u[j] && (minn[j] < minn[k]))
k = j;
u[k] = false; //蓝点k加入生成树，标记为白点
for (j = 1; j <= n; j++) //修改与k相连的所有蓝点
if (u[j] && (g[k][j] < minn[j]))
minn[j] = g[k][j];
}
int total = 0;
for (i = 1; i <= n; i++) //累加权值
total += minn[i];
cout << total << endl;
return 0;
}
