#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define mod 1000000007ll
#define loop(i, n) for (int i = 0; i < n; i++)
#define all(v) v.begin(), v.end()
#define putout(a) cout << a << '\n'
#define Sum(v) accumulate(all(v), 0ll)
void bfs(vector<vector<ll>> &G, vector<ll> &dist, ll s)
{
    queue<ll> que;
    dist[s] = 0;
    que.push(s);
    while (!que.empty())
    {
        ll v = que.front();
        que.pop();
        for (auto next_v : G[v])
        {
            if (dist[next_v] != -1)
                continue;
            dist[next_v] = dist[v] + 1;
            que.push(next_v);
        }
    }
}
vector<ll> sz;
void dfs(vector<vector<ll>> &G, ll v, ll p)
{
    for (auto nv : G[v])
    {
        if (nv == p)
            continue;
        dfs(G, nv, v);
    }
    sz[v] = 1;
    for (auto nv : G[v])
    {
        if (nv == p)
            continue;
        sz[v] += sz[nv];
    }
}
int main()
{
    ll N;
    cin >> N;
    vector<vector<ll>> G(N);
    ll root = 0; //bとして1度も出現しないのが根
    sz.resize(N);
    vector<ll> A(N - 1), B(N - 1), x(N - 1), y(N - 1), used(N, false);
    loop(i, N - 1)
    {
        cin >> A[i] >> B[i];
        A[i]--;
        B[i]--;
        used[B[i]] = true;
        G[A[i]].emplace_back(B[i]);
    }
    loop(i, N) if (!used[i]) root = i;
    vector<ll> dist(N, -1);
    bfs(G, dist, root);
    dfs(G, root, -1);
    loop(i, N - 1) x[i] = dist[B[i]]; //dist[A[i]]+1でもよい
    loop(i, N - 1) y[i] = sz[B[i]];
    ll ans = 0;
    loop(i, N - 1)
    {
        ans += x[i] * y[i] % mod;
        ans %= mod;
    }
    putout(ans);
    return 0;
}