#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>

using namespace std;
typedef long long ll;
ll N;
int par[1000001];
const ll MOD = 1000000007;

vector<int> G[1000000];
bool used[1000000];
ll ans;
void dfs(int v,ll d){
    used[v] = true;
    ans += (d*(d+1))/2;
    for(int to : G[v]){
        if(!used[to]) dfs(to, d+1);
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    cin >> N;
    for(int i = 0; i < N-1; i++){
        int a, b; cin >> a >> b;
        par[b] = a;
        a--; b--;
        G[a].push_back(b); G[b].push_back(a);
    }
    int r;
    for(int i = 1; i <= N; i++){
        if(par[i] == 0){
            r = i-1;
            break;
        }
    }
    dfs(r, 0);
    cout << ans%MOD << endl;
}