#define _USE_MATH_DEFINES #include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define MT make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)<; using vi = vector; using vll = vector; template class ModInt { public: ModInt() :value(0) {} ModInt(long long val) :value((int)(val<0 ? MOD + val % MOD : val % MOD)) { } ModInt& operator+=(ModInt that) { value = value + that.value; if (value >= MOD)value -= MOD; return *this; } ModInt& operator-=(ModInt that) { value -= that.value; if (value<0)value += MOD; return *this; } ModInt& operator*=(ModInt that) { value = (int)((long long)value * that.value % MOD); return *this; } ModInt &operator/=(ModInt that) { return *this *= that.inverse(); } ModInt operator+(ModInt that) const { return ModInt(*this) += that; } ModInt operator-(ModInt that) const { return ModInt(*this) -= that; } ModInt operator*(ModInt that) const { return ModInt(*this) *= that; } ModInt operator/(ModInt that) const { return ModInt(*this) /= that; } ModInt pow(long long k) const { ModInt n = *this, res = 1; while (k) { if (k & 1)res *= n; n *= n; k >>= 1; } return res; } ModInt inverse() const { long long a = value, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } int toi() const { return value; } private: int value; }; typedef ModInt<1000000007> mint; ostream& operator<<(ostream& os, const mint& x) { os << x.toi(); return os; } namespace comb { const int N = 200005; mint fact[N]; mint rev[N]; void init() { fact[0] = 1; for (int i = 1; i < N; ++i)fact[i] = fact[i - 1] * i; for (int i = 0; i < N; ++i)rev[i] = fact[i].inverse(); } mint C(int n, int r) { if (n < r)return 0; return fact[n] * rev[r] * rev[n - r]; } mint H(int n, int r) { return C(n + r - 1, r); } mint P(int n, int r) { assert(n >= r); return fact[n] * rev[n - r]; } mint catalan(int n) { return fact[2 * n] * rev[n + 1] * rev[n]; } } int N; vi T[200005]; mint ans; void dfs(int u, int d, int p) { ans += comb::C(N, d) * comb::fact[N - d] * comb::fact[d - 1]; each(v, T[u]) { if (v != p) { dfs(v, d + 1, u); } } } void solve() { comb::init(); cin >> N; rep(i, N - 1) { int u, v; cin >> u >> v; T[u].push_back(v); T[v].push_back(u); } dfs(1, 1, -1); cout << ans << endl; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(15); solve(); return 0; }