#!/usr/bin/env python3 # %% import sys read = sys.stdin.buffer.read readline = sys.stdin.buffer.readline readlines = sys.stdin.buffer.readlines # %% import numpy as np MOD = 10**9 + 7 # %% N = int(readline()) m = map(int, read().split()) UV = zip(m, m) # %% G = [[] for _ in range(N + 1)] for u, v in UV: G[u].append(v) G[v].append(u) # %% def cumprod(A, MOD=MOD): L = len(A) Lsq = int(L**.5 + 1) A = np.resize(A, Lsq**2).reshape(Lsq, Lsq) for n in range(1, Lsq): A[:, n] *= A[:, n - 1] A[:, n] %= MOD for n in range(1, Lsq): A[n] *= A[n - 1, -1] A[n] %= MOD return A.ravel()[:L] def make_fact(U, MOD=MOD): x = np.arange(U, dtype=np.int64) x[0] = 1 fact = cumprod(x, MOD) x = np.arange(U, 0, -1, dtype=np.int64) x[0] = pow(int(fact[-1]), MOD - 2, MOD) fact_inv = cumprod(x, MOD)[::-1] fact.flags.writeable = False fact_inv.flags.writeable = False return fact, fact_inv # %% fact, fact_inv = make_fact(2 * 10**5 + 10) inv = np.zeros_like(fact) inv[1:] = fact[:-1] * fact_inv[1:] % MOD inv = inv.tolist() # %% depth = [0] * (N + 1) depth[1] = 1 stack = [1] while stack: v = stack.pop() for w in G[v]: if depth[w]: continue depth[w] = depth[v] + 1 stack.append(w) # %% x = 0 for d in depth[1:]: x += inv[d] x %= MOD x *= fact[N] x %= MOD print(x)