#include<iostream>
#include<cstring>
using namespace std;
const int N=3005;
#define inf 0x3f3f3f3f
int fa[N];
int sum[N];
int n,m;
int find(int x)
{
    if(fa[x]==x)
       return x;
    return fa[x]=find(fa[x]);
}
bool merge(int x,int y)
{
     int fx=find(x);
     int fy=find(y);
     if(fx!=fy)
     {
          fa[fx]=fy;
          return true;
     }
      return false; 
}
int main()
{
    while(~scanf("%d%d",&n,&m))
    {
        int ans=n-1;
        memset(sum,0,sizeof(sum));
        for(int i=0;i<N;i++)
           fa[i]=i;
        int u,v,w;
        while(m--)
        {
            scanf("%d%d%d",&u,&v,&w);
            if(u==v) continue;
            sum[u]+=w;
            sum[v]+=w;
            if(merge(u,v)) ans--;
        }
        if(ans!=0) cout<<"0"<<endl;
        else
        {
            int min=inf;
            for(int i=1;i<=n;i++)
               if(min>sum[i])
                  min=sum[i];
            cout<<min<<endl; 
        }
    }     
    return 0;
}