#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define int long long #define all(a) a.begin(),a.end() #define rep(i, n) for (ll i = 0; i < (n); i++) #define pb push_back #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef pair P; typedef complex com; constexpr int inf = 1000000010; constexpr ll INF = 1000000000000000010; constexpr ld eps = 1e-12; constexpr ld pi = 3.141592653589793238; template inline bool chmax(T &a, const U &b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T &a, const U &b) { if (a > b) { a = b; return true; } return false; } vector> graph(1000010, vector()); vector cnt(1000010), sz(1000010, 1); void dfs(int n) { for (int i : graph[n]) { dfs(i); cnt[n] += cnt[i]; sz[n] += sz[i]; } cnt[n] += sz[n] - 1; } signed main() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); int n; cin >> n; graph.resize(n); cnt.resize(n); sz.resize(n); vector a(n); rep(i, n - 1) { int u, v; cin >> u >> v; u--; v--; graph[u].pb(v); a[v] = true; } int root = -1; int s = 0; rep(i, n) { if (!a[i]) root = i, s++; } assert(s == 1); dfs(root); assert(0 <= root && root < n); ll ans = 0; rep(i, n) { ans += cnt[i]; assert(sz[i] >= 1); assert(cnt[i] >= 0); } cout << ans << '\n'; }