import sys
sys.setrecursionlimit(10**8)
input=sys.stdin.readline

def dfs(v,depth,mod):
    ans[0] += depth*(depth+1)//2
    ans[0] %= mod
    for u in edge[v]:
        dfs(u,depth+1,mod)
    return

N = int(input())
mod = 10**9+7
edge = [[] for _ in range(N)]
roots = [True]*N
for _ in range(N-1):
    a,b = map(int, input().split())
    roots[b-1] = False
    edge[a-1].append(b-1)
nums = [-1]*N
child = [-1]*N
root = roots.index(True)
ans = [0]
dfs(root,0,mod)
print(ans[0])