#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <math.h>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
#include <stack>
#include <queue>

typedef unsigned long long ULLONG;
typedef long long LLONG;
static const LLONG MOD_NUM = 1000000007;//998244353;

template<class _T> static void getval(_T& a) {
	std::cin >> a;
}
template<class _T> static void getval(_T& a, _T& b) {
	std::cin >> a >> b;
}
template<class _T> static void getval(_T& a, _T& b, _T& c) {
	std::cin >> a >> b >> c;
}

static void exec();

int main()
{
	exec();
	fflush(stdout);
	return 0;
}

static LLONG dfs(std::vector<std::vector<int>>& graph, int here, int pass)
{
	LLONG ans = 0;
	for (auto it = graph[here].begin(); it != graph[here].end(); it++) {
		ans = (ans + dfs(graph, *it, pass + 1)) % MOD_NUM;
	}
	ans += (pass * (pass + 1) / 2LL) % MOD_NUM;
	ans %= MOD_NUM;

	return ans;
}

static void exec()
{
	int N;
	getval(N);

	std::set<int> vers;
	for (int i = 0; i < N; i++) {
		vers.insert(i);
	}
	std::vector<std::vector<int>> graph(N);
	for (int i = 1; i < N; i++) {
		int a, b;
		getval(a, b); a--; b--;
		graph[a].push_back(b);
		vers.erase(b);
	}

	printf("%lld\n", dfs(graph, *(vers.begin()), 0));
}