n=int(input())
mod=10**9+7
es=[[] for _ in range(n)]
par=[-1]*n
for _ in range(n-1):
    a,b=map(int,input().split())
    es[a-1].append(b-1)
    if par[b-1]==-1:
        par[b-1]=a-1

for i in range(n):
    if par[i]==-1:
        root=i
        break

new=[]
# dfs
from collections import deque, Counter
stack=deque([(root,0)])
ans=0
while stack:
    now,depth=stack.pop()
    new.append((now,depth))
    for e in es[now]:
        stack.append((e, depth+1))
        ans+=(depth+1)*(depth+2)//2
        ans%=mod
print(ans%mod)