#include<stdio.h>
#include<algorithm>

using namespace std;
const int N = 3e3 + 10;
typedef long long ll;
int f[N];
ll v[N];

int find(int x){
    if(x == f[x]) return x;
    return f[x] = find(f[x]);
}

int main(){
    int n,m;
    while(~scanf("%d %d",&n,&m)) {
        int L = 0;
        for(int i=1;i<=n;i++) f[i] = i,v[i] = 0;
        for(int i=0;i<m;i++) {
            int a,b,c;
            scanf("%d %d %d",&a,&b,&c);
            if(a == b) continue;
            int x = find(a);
            int y = find(b);
            v[a] += c;
            v[b] += c;
            if(x != y) {
                L ++;
                f[x] = y;
            }
        }
        if(L != n - 1) printf("0\n");
        else {
            ll res = 0x3f3f3f3f3f3f3f3f;
            for(int i=1;i<=n;i++) res = min(res,v[i]);
            printf("%lld\n",res);
        }
    }
    return 0;
}