#include <bits/stdc++.h> using namespace std; #define ll long long #define vt vector #define it int #define fi first #define se second #define bl bool vt<pair<it, it>> adj[100005]; it n, m; void hehe() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); } bool isPath(it maxT) { priority_queue<pair<it, it>, vector<pair<it, it>>, greater<pair<it, it>>> pq; vt<it> maxE(n + 1, INT_MAX); maxE[1] = 0; pq.push({ 0, 1 }); while (!pq.empty()) { auto [cMax, u] = pq.top(); pq.pop(); if (u == n) return true; for (auto &e : adj[u]) { it v = e.fi, w = e.se; if (w <= maxT) { it newMax = max(cMax, w); if (newMax < maxE[v]) { maxE[v] = newMax; pq.push({ newMax, v }); } } } } return false; } signed main(void) { hehe(); cin >> n >> m; for (it i = 0; i < m; ++i) { it u, v, w; cin >> u >> v >> w; adj[u].push_back({ v, w }); adj[v].push_back({ u, w }); } it l = 1, r = INT_MAX, res = INT_MAX; while (l <= r) { it mid = l + (r - l) / 2; if (isPath(mid)) { res = mid; r = mid - 1; } else { l = mid + 1; } } cout << res << endl; return 0; } // 1 con nai