#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i,l,r) for(ll i=(l);i<(r);++i)
#define REP(i,n) FOR(i,0,n)
#define REPS(i,n) FOR(i,1,n+1)
#define RFOR(i,l,r) for(ll i=(l);i>=(r);--i)
#define RREP(i,n) RFOR(i,n-1,0)
#define RREPS(i,n) RFOR(i,n,1)
#define pb push_back
#define eb emplace_back
#define SZ(x) ((ll)(x).size())
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
template<class T = ll> using V = vector<T>;
template<class T = ll> using VV = V<V<T>>;
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true; }return false; }
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true; }return false; }
inline void Yes(bool b = true) {cout << (b ? "Yes" : "No") << '\n';}
inline void YES(bool b = true) {cout << (b ? "YES" : "NO") << '\n';}
inline void err(bool b = true) {if(b) {cout << -1 << '\n'; exit(0);}}
template<class T> inline void fin(bool b = true, T e = 0) {if(b) {cout << e << '\n'; exit(0);}}
template<class T> T Roundup_div(T x, T y) {return (x+(y-1))/y;}
const ll INF = 1e18;
const int NAX = 1e6;

VV<> G(NAX);

int ans;

int dfs(int r, int depth = 0){
    int res = 0;
    for(auto v:G[r]){
        res += 1 + dfs(v, depth + 1);
    }
  	ans += res * (depth + 1);
    return res;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n; cin >> n;
    V<bool> c(n,true);
    REP(i,n-1){
        int a, b; cin >> a >> b; a--; b--;
        G[a].pb(b);
        c[b] = false;
    }
    int root;
    REP(i,n) if(c[i]){
        root = i;
        break;
    }
    dfs(root);
    cout << ans << endl;
}