#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;

const int N = 3e3+6;;

int pre[N], val[N];

int found(int x)
{
    int f = pre[x];
    while(f != x){
        x = f;
        f = pre[x];
    }
    return f;
}

int main()
{
    int n, m, u, v, w, i;
    while(~scanf("%d%d", &n, &m)){
        memset(val, 0, sizeof val);
        int cnt = n-1;
        for(i = 0; i < N; ++i)
            pre[i] = i;
        while(m--){
            scanf("%d%d%d", &u, &v, &w);
            if(u == v)
                continue;
            val[u] += w;
            val[v] += w;
            int x = found(u), y = found(v);
            if(x != y){
                --cnt;
                pre[x] = y;
            }
        }
        if(!cnt){
            sort(val+1, val+n+1);
            printf("%d\n", val[1]);
        }
        else
            printf("0\n");
    }
    return 0;
}