#include <stdio.h>
#include <iostream>
#include <string.h>
#include <algorithm>
#include <map>
using namespace std;
int fa[3100],sum[3100];

int find1(int x)
{
    if(x!=fa[x])return find1(fa[x]);
    else return x;
}
 
int main()
{
    int n,m;
    while(~scanf("%d%d", &n, &m)) {
        for(int i=1; i<=n; i++)
            fa[i]=i,sum[i]=0;
        int u,v,w;
        int cnt=n-1;
        for(int i=1;i<=m;i++) { 
            scanf("%d%d%d",&u,&v,&w);
            if(u==v)
                continue;
            sum[u]+=w;
            sum[v]+=w;
            int a,b;
            a=find1(u);
            b=find1(v);
            if(a!=b) {
                cnt--;
                fa[a]=fa[b];
            }
        }
        sort(sum+1,sum+1+n);
        if(cnt!=0)
            printf("0\n");
        else 
            printf("%d\n",sum[1]);
    }
    return 0;
}