def main():
    from collections import deque
    import sys
    input = sys.stdin.readline
    N = int(input())
    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)

    ans = 0
    mod = 10**9+7
    d = deque()
    root = roots.index(True)
    d.append([root,0])
    while len(d)>0:
        v,depth = d.popleft()
        ans += depth*(depth+1)//2
        ans %= mod
        for w in edge[v]:
            d.append([w,depth+1])
    print(ans)

if __name__ == '__main__':
    main()