from collections import deque N = int(input()) E = [[] for _ in range(N)] par = [-1]*N for _ in range(N-1): a,b = map(int, input().split()) E[a-1].append(b-1) par[b-1] = a-1 for i in range(N): if par[i] == -1: root = i break ans = 0 mod = 10**9+7 q = deque() q.append((root, 0)) while q: temp = q.pop() p = temp[0] rnk = temp[1] ans += rnk*(rnk+1)//2 ans %= mod for v in E[p]: q.append((v, rnk+1)) print(ans)