#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int maxn = 2e5 + ;

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] = ;

    son[u] = ;

    son[u]++;

    even[u] = ;

    for(int i = ; 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 = ;

void dfs2(int u, int fa)

{

    for(int i = ; 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 = ; i <= n - ; i++)

    {

        int u, v; scanf("%d %d", &u, &v);

        g[u].push_back(v);

        g[v].push_back(u);

    }

    dfs1(, );

    dfs2(, );

    ans += (d[] + odd[]) / 2LL;

    printf("%lld\n", ans / 2LL);

    return ;

}

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int maxn = 2e5 + ;

vector<int> g[maxn];

int n;

ll ans, odd, even;

int dfs(int u, int fa, int dep)

{

    if(dep % ) odd++;

    else even++;

    int son = ; ///统计子树大小

    for(int i = ; i < (int)g[u].size(); i++)

    {

        int v = g[u][i];

        if(v == fa) continue;

        int sing = dfs(v, u, dep + );

        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 = ; i <= n - ; i++)

    {

        int u, v; scanf("%d %d", &u, &v);

        g[u].push_back(v);

        g[v].push_back(u);

    }

    dfs(, , );

    ans = (ans + (ll)odd * even) / ;

    printf("%lld\n", ans);

    return ;

}