#include using namespace std; #define rep(i,n) for(ll i=0;i=0;i--) #define perl(i,r,l) for(ll i=r-1;i>=l;i--) #define fi first #define se second #define pb push_back #define ins insert #define pqueue(x) priority_queue,greater> #define all(x) (x).begin(),(x).end() #define CST(x) cout<> #define rev(x) reverse(x); using ll=long long; using vl=vector; using vvl=vector>; using pl=pair; using vpl=vector; using vvpl=vector; const ll MOD=1000000007; const ll MOD9=998244353; const int inf=1e9+10; const ll INF=4e18; const ll dy[8]={1,0,-1,0,1,1,-1,-1}; const ll dx[8]={0,-1,0,1,1,-1,1,-1}; template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } ll ans=0; ll dfs(ll v,vvl &g,ll s=1){ ll t=1; for(auto nv:g[v]){ t+=dfs(nv,g,s+1); } ans+=(s-1)*t; return t; } int main(){ ll n;cin >> n; vvl g(n); unordered_set st; rep(i,n)st.ins(i); rep(i,n-1){ ll a,b;cin >> a>> b; a--;b--; st.erase(b); g[a].pb(b); } dfs(*st.begin(),g); cout << ans <