#include<bits/stdc++.h>
using namespace std;
int n, m;
int fa[N];
struct Node{
    int a, b, w;

    bool operator< (const Node &t) const{
        return w < t.w;
    }
}g[M];

int find(int x)
{
    if(fa[x] != x) fa[x] = find(fa[x]);
    return fa[x];
}

int kruskal()
{
    sort(g, g + m);
    for(int i = 1; i <= n; i++)
        fa[i] = i;
    
    int res = 0, cnt = 0;
    for(int i = 0; i < m; i++)
    {
        int a = g[i].a, b = g[i].b, w = g[i].w;
        a = find(a), b = find(b);
        if(a != b)
        {
            fa[a] = b;
            res += w;
            cnt ++;
        }
    }

    if(cnt < n - 1) return INF;
    return res;
}