Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const (
	MAX_N      = 200
	MAX_WEIGHT = 2000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	shortestList := make([]ShortestInfo, n)
	for i := 1; i < n; i++ {
		shortestList[i] = ShortestInfo{edges: []Edge{}, shortest: MAX_N*MAX_WEIGHT + 1}
	}

	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		adjacentMatrix[i] = make([]int, n)
		for j := 0; j < n; j++ {
			v, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjacentMatrix[i][j] = v
		}
	}

	mst([]int{1}, shortestList, adjacentMatrix)
	fmt.Println(calculateMinWeight(shortestList))
}

func calculateMinWeight(shortestList []ShortestInfo) int {
	visitedList := make([]bool, len(shortestList))
	visitedList[0] = true
	sumWeight := 0
	for !visitedAll(visitedList) {
		shortestInfo := shortestList[0]
		shortestList = shortestList[1:]
		edges := shortestInfo.edges
		for _, edge := range edges {
			if !visitedList[edge.end-1] {
				visitedList[edge.end-1] = true
				sumWeight += edge.weight
			}
		}
	}
	return sumWeight
}

func visitedAll(visitedList []bool) bool {
	for _, v := range visitedList {
		if !v {
			return false
		}
	}
	return true
}

func mst(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	for len(nodeStack) > 0 {
		currentNode := nodeStack[0]
		nodeStack = nodeStack[1:]
		currentShortest := getShortest(currentNode, shortestList)
		adjacents := findAdjacents(currentNode, adjacentMatrix)
		for i := 0; i < len(adjacents); i++ {
			adj := adjacents[i]
			s := getShortest(adj.end, shortestList)
			if currentShortest.shortest+adj.weight < s.shortest || (currentShortest.shortest+adj.weight == s.shortest && len(currentShortest.edges)+1 > len(s.edges)) {
				setShortest(adj.end, adj, currentShortest, shortestList)
				nodeStack = append(nodeStack, adj.end)
			}
		}
	}
}

func getShortest(node int, shortestList []ShortestInfo) ShortestInfo {
	return shortestList[node-1]
}

func setShortest(node int, edge Edge, currentShortest ShortestInfo, shortestList []ShortestInfo) {
	newEdges := make([]Edge, len(currentShortest.edges)+1)
	for i := 0; i < len(newEdges)-1; i++ {
		newEdges[i] = currentShortest.edges[i]
	}
	newEdges[len(newEdges)-1] = edge
	shortestInfo := ShortestInfo{edges: newEdges, shortest: currentShortest.shortest + edge.weight}
	shortestList[node-1] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode-1]
	edges := []Edge{}
	for i, v := range adjacents {
		if v > 0 {
			edges = append(edges, Edge{start: currentNode, end: i + 1, weight: v})
		}
	}
	return edges
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <cassert>

#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
// #include <boost/foreach.hpp>
// #include <boost/range/algorithm.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
//#define INF 1e9
#define LINF 1e18
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define int long long
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
struct edge{int to,cost;};
//typedef pair<int,int> P;

const long long MOD=1000000007LL;
bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool isPrime(int x){if(x==1)return 0;if(x==2)return 1;if(x%2==0)return 0;for(int i=3;i*i<=x;i++)if(x%i==0)return 0;return 1;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}
bool isnumber(char c){return ('0'<=c&&c<='9');}
bool isalpha(char c){return (isupper(c)||islower(c));}
template<typename T> 
void print(vector<T> v){
    for(int i=0;i<v.size();i++){
        if(i)cout<<" ";
        cout<<v[i];
    }
    cout<<endl;
}
int INF=1e18;

template<typename T>
void printendl(vector<T> v){
    for(auto date:v)cout<<date<<endl;
}

template<typename T>
void printvv(vector<vector<T>> v){
    for(int i=0;i<v.size();i++){
        for(int j=0;j<v[i].size();j++){
            if(j)cout<<" ";
            cout<<v[i][j];
        }
        cout<<endl;
    }
}
int gcd(int a,int b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    else return gcd(b,a%b);
}

struct Edge{
    int to,cost;
};

int prim(vector<vector<Edge>>& g, int n){
    typedef pair<int,int> P;
    vector<bool> used(n+1,false);
    int ret=0;
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, 0)); //(コスト, 頂点)
    while(!que.empty()){
        P p=que.top();
        que.pop();
        if(used[p.second])continue;
        used[p.second]=true;
        ret+=p.first;
        for(int i=0;i<g[p.second].size();i++){
            Edge e=g[p.second][i];
            que.push(P(e.cost, e.to));
        }
    }
    return ret;
}

signed main (){
    int n;
    cin>>n;
    vector<vector<Edge>> v(n,vector<Edge>(0));
    rep(i,0,n){
        rep(j,0,n){
            int x;
            cin>>x;
            if(x!=-1){
                v[i].push_back(Edge{j,x});
            }
        }
    }
    cout<<prim(v,n)<<endl;

}
/*

*/