#pragma GCC optimize("O3") //#pragma GCC target("avx2") //#pragma GCC optimize("unroll-loops") #include using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef vector vi; typedef vector vll; typedef vector vld; typedef pair Pll; typedef pair Pin; ll INF = 1e16; int inf = 1e9; #define ALL(x) (x).begin(), (x).end() #define FOR(i, m, n) for (ll i = (m); i < (n); ++i) #define REVFOR(i, m, n) for (ll i = (n - 1); i >= (m); --i) #define REP(i, n) FOR(i, 0, n) #define REVREP(i, n) REVFOR(i, 0, n) #define fi first #define se second #define pb push_back #define mp make_pair #define eb emplace_back #define bcnt __builtin_popcountll #ifdef LOCAL #include #define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", d_err(__VA_ARGS__); #else #define debug(...) 83; #endif void d_err() { cerr << endl; } template void d_err(H h, T... t) { cerr << h << " "; d_err(t...); } template void print(T x) { cout << x << "\n"; } template void print(vector& x) { int N = x.size(); REP(i, N) { if (i > 0) cout << " "; cout << x[i]; } cout << "\n"; } int main(){ cin.tie(0); ios_base::sync_with_stdio(false); cout << fixed << setprecision(20); int n; cin >> n; vector edge(n); REP(i, n-1) { int a, b; cin >> a >> b; a--, b--; edge[a].eb(b); edge[b].eb(a); } vll dp(n); ll ans = 0; auto dfs = [&](auto &&f, int cur, int par = -1) -> void { dp[cur]++; for(auto &e: edge[cur]) { if (e == par) continue; f(f, e, cur); dp[cur] += dp[e]; ans += dp[e] * (n - dp[e]); } ans += (n - dp[cur]) * dp[cur]; ans += n; }; dfs(dfs, 0); print(ans); }