#include <bits/stdc++.h>
#define rep(i,n) for(ll i = 0; i < n; i++) //[0,n)
#define srep(i,a,b) for(ll i = a; i < b; i++) //[a,b)
#define all(A) (A).begin(),(A).end()
#define rall(A) (A).rbegin(),(A).rend()
#define pmt(A) next_permutation(all(A))
using namespace std;
using ll = long long;
using ull = unsigned long long;
using P = pair<ll,ll>;
using pq = priority_queue<P,vector<P>,greater<P>>;
const ll inf = 1LL<<60;
const int iinf = (int)1e9+1;
const int mod9 = 998244353;
const int mod1 = 1000000007;
struct Edge { int to; long long cost; int from; };
bool compe(const Edge &e,const Edge &e2){ return e.cost < e2.cost; }
using Graph = vector<vector<int>>;
using SGraph = vector<set<ll>>;
template <class T>
int siz(T& a){return (int)a.size();}
ll squa(ll a){ return a*a; }
ll mceil(ll a,ll b){ return (a+b-1)/b; }

void dfs(const Graph &G,vector<int> &dist,int v,int d,int pre = -1){
    if(siz(G[v]) == 0) return;

    for(auto nv : G[v]){
        if(nv == pre) continue;
        dist[nv] = d+1;
        dfs(G,dist,nv,d+1,v);
    }
}

ll nC2(ll n){ return n*(n-1)/2; }

int main(void){
    int N; cin >> N;
    Graph G(N);
    rep(i,N-1){
        int u,v; cin >> u >> v;
        u--; v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }

    vector<int> dist(N,0),cnt(101010,0);
    dfs(G,dist,0,0);

    rep(i,N) cnt[dist[i]]++;

    ll ans = 0;
    rep(i,N) ans += cnt[dist[i]+1]+cnt[dist[i]+2]+cnt[dist[i]+3];
    cout << ans;
}