#define rep(i, a, n) for (int i = a; i < n; ++i) #define per(i, a, n) for (int i = n - 1; i >= a; --i) #define fi first #define pb push_back #define mp make_pair #define EPS 1e-8 #define INF 0x3f3f3f3f3f #define endl '\n' #define all(x) x.bgein(), x.end()
constint maxn = 2e4 + 5; constint maxm = 2e5 + 5; structEdge { int u, v, w; Edge(int _u, int _v, int _w) : u(_u) , v(_v) , w(_w) { } Edge() {} booloperator<(const Edge b) { return w > b.w; } } p[maxm];
vector<pii> e[maxn]; int n, m, k, t, vis[maxn];
inlinevoidinit() { rep(i, 0, n + 1) e[i].clear(); }
booldfs(int x, int co) { vis[x] = co; rep(i, 0, e[x].size()) { int y = e[x][i].first; if (vis[y] == co) return0; elseif (!vis[y] && !dfs(y, 3 - co)) return0; } return1; }
inlineboolpd(int mid) { init(); memset(vis, 0, sizeof(vis)); rep(i, 0, m) { if (p[i].w <= mid) break; e[p[i].u].pb(mp(p[i].v, p[i].w)); e[p[i].v].pb(mp(p[i].u, p[i].w)); } rep(i, 1, n + 1) { if (!vis[i] && !dfs(i, 1)) return0; } return1; }
intmain() { ios::sync_with_stdio(false); while (cin >> n >> m) { rep(i, 0, m) { cin >> p[i].u >> p[i].v >> p[i].w; } sort(p, p + m); int l = 0, r = p[0].w, mid; while (l < r) { mid = (l + r) >> 1; if (pd(mid)) r = mid; else l = mid + 1; } cout << l << endl; } }