60分求条

#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define int __int128
// #define int unsigned long long
const int N = 2e4 + 10, M = 1e5 + 10;
struct ren {
	int u, v, w;
} fan[M];
int fa[N];
int n, m;
bool cmp (ren x, ren y) {
	return x.w > y.w;
}
int find (int u) {
	if (fa[u] == u) return u;
	else return fa[u] = find (fa[u]);
}
void merge (int u, int v) {
	int fx = find (u), fy = find (v);
	if (fx != fy) {
		fa[fx] = fy;
	}
}
void query () {
	for (int i = 1; i <= n; i++) fa[i] = i;
	sort (fan + 1, fan + 1 + m, cmp);
	for (int i = 1; i <= m; i++) {
		int fx = find (fan[i].u), fy = find (fan[i].v);
		if (fx == fy) {
			cout << fan[i].w << "\n";
			return;
		} else {
			merge (fx, fy);
		}
	}
	cout << "0\n";
}
signed main () {
	ios::sync_with_stdio (false);
	cin.tie (0), cout.tie (0);
	cin >> n >> m;
	for (int i = 1; i <= m; i++) cin >> fan[i].u >> fan[i].v >> fan[i].w;
	query ();
	return 0;
}