#include <bits/stdc++.h>

#define cs(n) scanf("%d", &n)
#define F(i, j, k) for(int i = j; i <= k; ++i)
#define R(i, j, k) for(int i = j; i >= k; --i)

using namespace std;
using ll = long long;
const int MAXN = 3004;
const int INF = 0x3f3f3f3f;

int fa[MAXN];
int val[MAXN]; 

int find(int x) {
    return x == fa[x] ? x :
        fa[x] = find(fa[x]);
}

int main() {
    int n, m;
    while(~scanf("%d%d", &n, &m)) {
        F(i, 1, n) fa[i] = i, val[i] = 0;
        int u, v, w, fu, fv, tot = 0;
        F(i, 1, m) {
            cs(u); cs(v); cs(w);
            if(u == v) continue;
            val[u] += w; val[v] += w;
            fu = find(u); fv = find(v);
            if(fu != fv) {
                fa[fu] = fv; ++tot;
            }
        }
        if(tot != n - 1) {
            puts("0"); continue;
        }
        int ans = INF;
        F(i, 1, n) ans = min(ans, val[i]);
        printf("%d\n", ans);
     }
     return 0;
}