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#include "bits/stdc++.h" // Tomasz Nowak
using namespace std;     // University of Warsaw
using LL = long long;
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
#define ssize(x) int(x.size())
template<class A, class B> auto& operator<<(ostream &o, pair<A, B> p) {
	return o << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &o, T x) -> decltype(x.end(), o) {
	o << '{'; int i = 0; for(auto e : x) o << (", ")+2*!i++ << e; return o << '}';
}
#ifdef DEBUG
#define debug(x...) cerr << "[" #x "]: ", [](auto... $) {((cerr << $ << "; "), ...); }(x), cerr << '\n'
#else
#define debug(...) {}
#endif

mt19937 rng(43121234);

vector<vector<pair<int, int>>> graph;
constexpr LL inf = LL(1e18);

array<LL, 4> dfs(int v, int p) {
	vector<array<LL, 4>> sons_values;
	for(auto [u, w] : graph[v])
		if(u != p) {
			auto got = dfs(u, v);
			got = {
				max(got[0], got[3] + w),
				got[0] + w,
				got[1] + w,
				got[2] + w
			};
			sons_values.emplace_back(got);
		}

	const int max_diff = min(ssize(sons_values) + 1, 1000);
	vector<array<LL, 2>> dp(2 * max_diff + 1, array<LL, 2>{{-inf, -inf}});
	auto new_dp = dp;
	dp[max_diff][0] = 0;

	for(const auto &got : sons_values) {
		FOR(d, 0, 2 * max_diff)
			for(int parity2 : {0, 1})
				new_dp[d][parity2] = dp[d][parity2] + got[0];
		FOR(d, 0, 2 * max_diff)
			for(int parity2 : {0, 1}) {
				if(d != 0)
					new_dp[d][parity2] = max(new_dp[d][parity2], dp[d - 1][parity2] + got[1]);
				if(d != 2 * max_diff)
					new_dp[d][parity2] = max(new_dp[d][parity2], dp[d + 1][parity2] + got[3]);
				new_dp[d][parity2] = max(new_dp[d][parity2], dp[d][parity2 ^ 1] + got[2]);
			}
		swap(dp, new_dp);
	}
	return {
		dp[max_diff][0],
		dp[max_diff + 1][0],
		dp[max_diff][1],
		dp[max_diff - 1][0]
	};
}

int main() {
	cin.tie(0)->sync_with_stdio(0);

	int n;
	cin >> n;
	graph.resize(n);
	REP(edge, n - 1) {
		int v, u, w;
		cin >> v >> u >> w;
		--v, --u;
		graph[v].emplace_back(u, w);
		graph[u].emplace_back(v, w);
	}
	for(auto &v : graph)
		shuffle(v.begin(), v.end(), rng);

	cout << dfs(0, -1)[0] << '\n';
}