import sys sys.setrecursionlimit(400000) MOD = 1000000007 inv2 = 500000004 def dfs0(i, prev) : subtree_dsum[i] = inv2 for j in hen[i] : if j != prev : dfs0(j, i) subtree_dsum[i] = (subtree_dsum[i] + subtree_dsum[j] * inv2) % MOD; res = 0 def dfs1(i, prev, prev_dsum) : global res all = [] if prev != -1 : all.append(prev_dsum) for j in hen[i] : if j != prev : all.append(subtree_dsum[j]) sum1 = sum(all) % MOD sum2 = sum(map(lambda i : i * i, all)) % MOD sum3 = sum(map(lambda i : i * i * i, all)) % MOD res = (res \ + sum1 * sum1 * sum1 - sum2 * sum1 * 3 + sum3 * 2 \ + (sum1 * sum1 - sum2) * 3 \ + sum1 * 3 + 1) % MOD if res < 0 : res += MOD for j in hen[i] : if j != prev : next = (sum1 - subtree_dsum[j] + 1) * inv2 % MOD if next < 0 : next += MOD dfs1(j, i, next); n = int(input()) hen = [[] for i in range(n)] for i in range(n - 1) : a, b = map(int, input().split()) a -= 1 b -= 1 hen[a].append(b) hen[b].append(a) subtree_dsum = [0 for i in range(n)] dfs0(0, -1) dfs1(0, -1, 0) for i in range(n - 1) : res *= 2 if res >= MOD : res -= MOD print(res)