import collections
N = int(input())
lsg = [[] for i in range(N)]
per = [0]*(N)
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    lsg[a].append(b)
    per[b] += 1
r = -1
for i in range(N):
    if per[i] == 0:
        r = i
        break
d = collections.deque([r])
depth = [0]*(N)
while d:
    x = d.popleft()
    for j in lsg[x]:
        depth[j] = depth[x]+1
        d.append(j)
ans = 0
for i in range(N):
    ans += (depth[i])*(depth[i]+1)//2
print(ans%(10**9+7))