//prim算法求最小生成树
#include <iostream>
#include <cstring>
using namespace std;
const int N = 5010, INF = 0x3f3f3f3f;
int n, m, d[N], g[N][N];
bool st[N];

int prime()
{
    memset(d, 0x3f, sizeof d);
    int res = 0;
    for(int i = 0; i < n; i ++)
    {
        int t = -1;
        for(int j = 1; j <= n; j ++)
            if(!st[j] && (t == -1 || d[t] > d[j]))
                t = j;
        st[t] = true;
        if(i){
            if(d[t] == INF) return INF;
            res += d[t];
        }
        for(int j = 1; j <= n; j ++)
            if(d[j] > g[t][j])
                d[j] = g[t][j];
    }

    return res;
}

int main()
{
    cin >> n >> m;
    memset(g, 0x3f, sizeof g);

    while(m --)
    {
        int a, b, c;
        cin >> a >> b >> c;
        g[a][b] = g[b][a] = min(g[a][b], c);
    }

    int t = prime();
    if(t == INF) cout << "orz" << endl;
    else cout << t << endl;
}