ABC 361

void solve() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<vector<pair<ll, ll>>> graph(N);
    vll C;
    rep(i, N - 1) {
        int a, b, c;
        cin >> a >> b >> c;
        a--, b--;
        C.push_back(c);
        graph[a].push_back({b, c});
        graph[b].push_back({a, c});
    }

    vll dist(N);
    auto dfs = [&](auto dfs, int now, int p) -> void {
        for (auto [nx, c] : graph[now]) {
            if (nx == p) continue;
            dist[nx] = dist[now] + c;
            dfs(dfs, nx, now);
        }
    };

    dfs(dfs, 0, -1);
    int s = -1;
    ll d = -1;
    rep(i, N) {
        if (d < dist[i]) {
            d = dist[i];
            s = i;
        }
    }

    rep(i, N) dist[i] = 0;
    dfs(dfs, s, -1);
    d = -1;
    rep(i, N) {
        if (d < dist[i]) {
            d = dist[i];
        }
    }

    ll ans = accumulate(all(C), 0ll);
    ans *= 2;
    ans -= d;
    cout << ans << endl;
}