// 度度熊的王国战略2.cpp  运行/限制：140ms/2000ms
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
using namespace std;
int n, m, fa[3005], sum[3005];
int get(int x) {
    return fa[x] = fa[x] == x ? x : get(fa[x]);
}
void merge(int x, int y) {
    int a = get(x);
    int b = get(y);
    if (a != b) {
        fa[b] = a;
    }
}
void init() {
    for (int i = 1; i <= n; i++) {
        fa[i] = i;
    }
}
int main(){
    int a, b, c, cnt;
    while (scanf("%d%d", &n, &m) != EOF) {
        init();
        cnt = n - 1;
        memset(sum, 0, sizeof(sum));
        for (int i = 0; i < m; i++) {
            scanf("%d%d%d", &a, &b, &c);
            if (a == b) continue;
            sum[a] += c;
            sum[b] += c;
            int x = get(a);
            int y = get(b);
            if (x != y) {
                merge(x, y);
                cnt--;
            }
        }
        if (cnt) {
            printf("0\n");
        }
        else{
            sort(sum + 1, sum + n + 1);
            printf("%d\n", sum[1]);
        }
    }
    return 0;
}