#include<iostream>
#include<algorithm>
#include<map>
#include<cstring>
#include<cstdio>
#define ll long long
#define lson (rt<< 1)
#define rson (rt<< 1 | 1)
#define gmid ((l+r)>> 1 )
using namespace std;

const int maxn=20050;
int n,m,u,v,w,f[maxn];
ll sum[maxn]; 
int find(int x)
{
    if(f[x]==x) return x;
    else return f[x]=find(f[x]);
}

bool merge(int x,int y)
{
    if(find(x)!=find(y))
    {
        f[find(y)]=find(x);
        return true;
    }
    return false;
}


int main()
{
    while(~scanf("%d%d",&n,&m))
    {
        int tot=n-1;
        memset(sum,0,sizeof(sum));
        for(int i=0;i<=n;++i)
          f[i]=i;
        while(m--)
        {
            cin>>u>>v>>w;
            if(u==v) continue;
            sum[u]+=w;
            sum[v]+=w;
            if(merge(u,v)) tot--;
        }   
        if(tot>0) cout<<"0"<<endl;
        else
        {
            int mn=maxn;
            for(int i=1;i<=n;++i)
              if(sum[i]<mn) mn=sum[i];
            cout<<mn<<endl;  
        }
    }
}