#include<bits/stdc++.h>
using namespace std;
struct tot{
    int a,b;
}lca[51];
struct sb{
    int k;
}lcb[51];
int n,m,cnt;
int c[51],h[51],jdb[21][21],x[51],y[51];
int main(){
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>lca[i].a>>lca[i].b>>lcb[i].k;
        if(lcb[i].k<lcb[i+1].k){
            swap(lcb[i].k,lcb[i+1].k);
            swap(lca[i].a,lca[i+1].a);
            swap(lca[i].b,lca[i+1].b);
        }
        c[lca[i].a]++;
        h[lca[i].b]++;
    }
    for(int i=1;i<=m;i++){
        if(c[lca[i].a]>=1&&h[lca[i].b]>=1&&x[i]==0&&y[i]==0){
            cnt=cnt+lcb[i].k;
            x[i]=1;
            y[i]=1;
        }
    }
    cout<<cnt;
    return 0;
} 

输出210