#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5 + 50;
vector<int> g[maxn];
int son[maxn];
ll d[maxn]; ///树内所有点到某个点的距离和
int odd[maxn];
int even[maxn];
void dfs1(int u, int fa)
{d[u] = 0;son[u] = 0;son[u]++;even[u] = 1;for(int i = 0; i < (int)g[u].size(); i++){int v = g[u][i];if(v == fa) continue;dfs1(v, u);son[u] += son[v];even[u] += odd[v];d[u] += d[v] + son[v];}odd[u] = son[u] - even[u];// printf("%d %I64d\n", u, d[u]);
}
ll ans = 0;
void dfs2(int u, int fa)
{for(int i = 0; i < (int)g[u].size(); i++){int v = g[u][i];if(v == fa) continue;d[v] = d[v] + (d[u] - d[v] - (ll)son[v]) + (ll)(son[u] - son[v]);odd[v] += (son[u] - son[v] - odd[u] + even[v]);son[v] = son[u];ans += ((d[v] + odd[v]) / 2LL);dfs2(v, u);}
}
int main()
{int n; scanf("%d", &n);for(int i = 1; i <= n - 1; i++){int u, v; scanf("%d %d", &u, &v);g[u].push_back(v);g[v].push_back(u);}dfs1(1, 0);dfs2(1, 0);ans += (d[1] + odd[1]) / 2LL;printf("%lld\n", ans / 2LL);return 0;
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5 + 50;
vector<int> g[maxn];
int n;
ll ans, odd, even;
int dfs(int u, int fa, int dep)
{if(dep % 2) odd++;else even++;int son = 1; ///统计子树大小for(int i = 0; i < (int)g[u].size(); i++){int v = g[u][i];if(v == fa) continue;int sing = dfs(v, u, dep + 1);ans += (ll)sing * (n - sing); ///枚举每条边的贡献son += sing;}return son;
}
int main()
{scanf("%d", &n);for(int i = 1; i <= n - 1; i++){int u, v; scanf("%d %d", &u, &v);g[u].push_back(v);g[v].push_back(u);}dfs(1, 0, 0);ans = (ans + (ll)odd * even) / 2;printf("%lld\n", ans);return 0;
}