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 <iostream>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <utility>
#include <functional>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <deque>
#include <ctime>

using namespace std;

#define rep(i,n) REP(i,0,n)
#define REP(i,s,e) for(int i=(s); i<(int)(e); i++)
#define pb push_back
#define mp make_pair
#define all(r) (r).begin(),(r).end()
#define rall(r) (r).rbegin(),(r).rend()
#define fi first
#define se second
#define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))


typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int INF = 1e9;
const ll LINF = 1e18;
const ll MOD = 1e9 + 7;
double EPS = 1e-8;
const double PI = acos(-1);

int dx[]={-1,1,0,0};
int dy[]={0,0,-1,1};

// ?????\?????????
// ?????°:?????????????´???°, ??????
// ???????????°????????§?????????????????´?£????????????´??????
// Down: ??????, Up: ??????
void insertionSortDown(int *a, int N){
    for(int i=1; i<N; i++){
        //???????????????,???????????????????´?????????????????????¨??????
        int v = a[i];
        int j = i - 1;

        //????????????????????¨?????¨??????????????????. ?????´??????????????????.
        while(j >= 0 && a[j] > v){
            a[j+1] = a[j];
            j--;
        }
        a[j+1] = v;

        /**
        cout << to_string(i) << "??????" << endl;
        for(int k=0; k<N; k++){
            cout << a[k] << endl;
        }
         **/
    }
}

void insertionSortUp(int *a, int N){
}

// ??????????????????
// ???????????´?£????????????´??????. ?????????????????°return?????????int???????????´??????
void bubbleSortUp(int *a, int N){
    int sw = 0;
    int flag = 1;

    while(flag == 1){
        flag = 0;

        for(int j=N-1; j>=sw; j--){
            if(a[j-1] > a[j]){
                swap(a[j-1], a[j]);
                flag = 1;
            }
        }
        sw++;
        //???????????´???????????????????????¨????????¨???????????£??????????????§.
    }
}

void selectionSortUp(int *a, int N){
    for(int i=0; i<N-1; i++){
        int minj = i;

        for(int j=i; j<N; j++){
            if(a[minj] > a[j]){
                minj = j;
            }
        }
        swap(a[minj], a[i]);
        //???????????´??§??????????????°??????????????????????????????,???????°????????????????????´???¨??????????????????
    }
}

// ?????¢??¢?´¢ O(nq)
// ??????, ?????????????´???°, ?????????????????????
bool linearSearch(int *a, int n,int key){
    int i = 0;
    a[n] = key; //??????????????????????????????

    while(a[i] != key) i++;

    //????´?????????????????????§??????????????°true?????????
    return i != n;
}



#define V_MAX 100
#define INFTY 5000
#define WHITE 0
#define GRAY 1
#define BLACK 2


int M[V_MAX][V_MAX];
int d[V_MAX], p[V_MAX];
int n;
int color[V_MAX];

int Prim(int u){
    p[u] = -1; //p??????????????????????¨????

    for(int i=0; i<n; i++){
        d[i] = INFTY;
        p[i] = -1;
        color[i] = WHITE;
    }

    d[u] = 0; //d?????????????????????

    while(1){
        int mincost = INFTY;
        int from = -1;

        //??????????????§???????°?????????¨??????????¨???¶????????????
        for(int i=0; i<n; i++){
            if(color[i] != BLACK && d[i] < mincost){
                mincost = d[i];
                from = i;
            }
        }

        if(from == -1) break;

        color[from] = BLACK;

        for(int v=0; v<n; v++){
            if(color[v] != BLACK && M[from][v] != INFTY){
                if(M[from][v] < d[v]){
                    d[v] = M[from][v];
                    p[v] = from; //???????¨??????????
                    color[v] = GRAY;
                }
            }
        }
    }

    int sum = 0;

    for(int j=0; j<n; j++){
       if(p[j] != -1) sum += M[j][p[j]];
    }

    return sum;
}

int main(){

    cin >> n;

    for(int k=0; k<n; k++) color[k] = WHITE;

    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++){
            int tmp;
            cin >> tmp;
            if(tmp != -1) M[i][j] = tmp;
            else M[i][j] = INFTY;
        }
    }

    int sum = Prim(0);

    cout << sum << endl;
}