import sys
from collections import deque

MOD = 10**9 + 7

def main():
    input = sys.stdin.read().split()
    ptr = 0
    N = int(input[ptr])
    ptr += 1
    
    par = [0] * (N + 1)  # 1-based index
    children = [[] for _ in range(N + 1)]
    
    for _ in range(N - 1):
        A = int(input[ptr])
        B = int(input[ptr + 1])
        ptr += 2
        par[B] = A
        children[A].append(B)
    
    # Find root (par[v] is 0)
    root = 0
    for v in range(1, N + 1):
        if par[v] == 0:
            root = v
            break
    
    depth = [0] * (N + 1)
    count = [0] * (N + 1)
    sum_depth = [0] * (N + 1)
    total = 0
    
    q = deque()
    q.append(root)
    
    while q:
        u = q.popleft()
        for v in children[u]:
            depth[v] = depth[u] + 1
            count[v] = count[u] + 1
            sum_depth[v] = sum_depth[u] + depth[u]
            contrib = (count[v] * depth[v] - sum_depth[v]) % MOD
            total = (total + contrib) % MOD
            q.append(v)
    
    print(total % MOD)

if __name__ == '__main__':
    main()