#include <bits/stdc++.h>
using namespace std;
 
vector<long long> A, AO, P, PE, PO;
vector<vector<int>> E;
 
void dfs(int u, int p)
{
    for (int v: E[u]) {
        if (v == p) {
            continue;
        }
 
        dfs(v, u);
 
        A[u] += A[v];
        AO[u] += AO[v];
 
        A[u] += P[v] + PE[v] + PO[v] + 1;
        AO[u] += PE[v] + 1;
 
        A[u] += P[u] * (PE[v] + PO[v] + 1) + (P[v] + PE[v] + PO[v] + 1) * (PE[u] + PO[u]);
        AO[u] += PO[u] * PO[v] + PE[u] * (PE[v] + 1);
 
        P[u] += P[v] + PE[v] + PO[v] + 1;
        PE[u] += PO[v];
        PO[u] += PE[v] + 1;
    }
}
 
int main()
{
    int n;
    cin >> n;
    E.assign(1 + n, vector<int>());
    for (int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v;
        E[u].push_back(v);
        E[v].push_back(u);
    }
    A.assign(1 + n, 0);
    AO.assign(1 + n, 0);
    P.assign(1 + n, 0);
    PE.assign(1 + n, 0);
    PO.assign(1 + n, 0);
    dfs(1, -1);
    cout << (A[1] - AO[1]) / 2 + AO[1] << endl;
    return 0;
}

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