#pragma region #pragma GCC target("avx2") #pragma GCC optimize("03") #pragma GCC optimize("unroll-loops") #include using namespace std; typedef long double ld; typedef long long ll; typedef unsigned long long ull; #define endl "\n" #define FOR(i,a,b) for(int i=(a);i<=(b);i++) #define rep(i,n) for(int i=0;i<(n);i++) #define PII pair #define PLL pair #define ALL(x) (x).begin(), (x).end() constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1; templateinline bool chmax(T &a, const T &b) { if (ainline bool chmin(T &a, const T &b) { if (b=(const mint a){return (x >= a.x)? 1: 0;} bool operator<(const mint a){return !(*this>=a);} bool operator>(const mint a){return (x > a.x)? 1:0;} bool operator<=(const mint a){return !(*this>a);} mint& operator+=(const mint a) { if ((x += a.x) >= mod) x -= mod; return *this; } mint& operator-=(const mint a) { if ((x += mod-a.x) >= mod) x -= mod; return *this; } mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this; } mint& operator/=(const mint a) { return (*this) *= a.inv(); } mint operator+(const mint a) const { mint res(*this); return res+=a; } mint operator-(const mint a) const { mint res(*this); return res-=a; } mint operator*(const mint a) const { mint res(*this); return res*=a; } mint operator/(const mint a) const { mint res(*this); return res/=a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t>>1); a *= a; //2 square if (t&1) a *= *this; return a; } // for prime mod mint inv() const { return pow(mod-2); } }; struct combination { vector fact, ifact; combination(int n):fact(n+1),ifact(n+1) { fact[0] = 1; for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i; ifact[n] = fact[n].inv(); for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i; } mint operator()(int n, int k) { if (k < 0 || k > n) return 0; return fact[n]*ifact[k]*ifact[n-k]; } } comb(200005); mint f(int n, int k) { if (n < 0) return 0; // nPk = nCk * k! mint res = comb(n,k); res *= comb.fact[k]; return res; } int n; constexpr int MX = 2e5+3; vector edges[MX]; vector visited(MX, false); mint ans(0); void dfs(int node, int rank) { ans += comb(n, rank)*comb.fact[rank-1]*comb.fact[n-rank]; // cout << ans.x << endl; visited[node] = true; for(auto &e: edges[node]) { if(!visited[e]) dfs(e, rank+1); } } int main(){ cin.tie(0); ios::sync_with_stdio(false); //cout << fixed << setprecision(15); cin >> n; rep(i,n-1) { int u, v; cin >> u >> v; edges[u].emplace_back(v); edges[v].emplace_back(u); } dfs(1,1); cout << ans.x << endl; return 0; }