#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
struct Edge {
	int to, cost;
	Edge(int _to, int _cost) :to(_to), cost(_cost) {}
};
vector<Edge>g[200005];
multiset<int>include, exclude;
void dfs(int v, int p = -1) {
	for (Edge e : g[v]) {
		if (p == e.to) continue;
		exclude.insert(e.cost);
		dfs(e.to, v);
	}
}
int anssub;
void dfs2(int v, int p = -1) {
	for (Edge e : g[v]) {
		if (p == e.to) continue;
		include.insert(e.cost);
		exclude.erase(exclude.find(e.cost));
		int x = *exclude.rbegin();
		int y = *include.begin();
		int z = *include.rbegin();
		chmin(anssub, max(x, z - y));
		dfs2(e.to, v);
		exclude.insert(e.cost);
		include.erase(include.find(e.cost));
	}
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	int s = 0, t = 0, w = 0;
	rep(i, n - 1) {
		int a, b, c; cin >> a >> b >> c; a--; b--;
		g[a].push_back({ b,c });
		g[b].push_back({ a,c });
		if (chmax(w, c)) s = a, t = b;
	}
	int ans = 0;
	rep(i, 2) {
		include.clear();
		exclude.clear();
		exclude.insert(0);
		include.insert(w);
		dfs(s, t);
		anssub = *exclude.rbegin();
		dfs2(s, t);
		chmax(ans, anssub);
		//cout << anssub << endl;
		swap(s, t);
	}
	cout << ans << endl;
	return 0;
}