import sys
from collections import defaultdict, deque, Counter
import math

# import copy
from bisect import bisect_left, bisect_right
import heapq

sys.setrecursionlimit(10000000)

# input aliases
input = sys.stdin.readline

getS = lambda: input().strip()
getN = lambda: int(input())
getList = lambda: list(map(int, input().split()))
getZList = lambda: [int(x) - 1 for x in input().split()]

INF = 10 ** 20
MOD = 10 ** 9 + 7
divide = lambda x: pow(x, MOD - 2, MOD)

ans = 0
def nck(n, k, kaijyo):
	return (npk(n, k, kaijyo) * divide(kaijyo[k])) % MOD


def npk(n, k, kaijyo):
	if k == 0 or k == n:
		return n % MOD
	return (kaijyo[n] * divide(kaijyo[n - k])) % MOD

def kaijyo(n):
	ret = [1]
	for i in range(1, n + 1):
		ret.append((ret[-1] * i)% MOD)
	return ret

def kaijyo_kai(n, k):
	ret = [1]
	for i in range(1, n + 1):
		ret.append((ret[-1] * (k+i))% MOD)
	return ret

def dfs(tree, cur, d):
	global ans
	ans += int(d * (d+1) // 2)
	for nx in tree[cur]:
		dfs(tree, nx, d + 1)


def solve():
	global ans
	n = getN()
	tree = [[] for i in range(n)]
	par = [0 for i in range(n)]
	for i in range(n-1):
		a, b = getZList()
		tree[a].append(b)
		par[b] = 1

	for i, tr in enumerate(par):
		if not tr:
			root = i
			break

	dfs(tree, root, 0)
	print(ans % MOD)

def main():
	n = getN()
	for _ in range(n):
		solve()


if __name__ == "__main__":
	# main()
	solve()