#include <bits/stdc++.h>
using namespace std;

#define rep(i,m,n) for(int (i)=(int)(m);i<(int)(n);++i)
#define rep2(i,m,n) for(int (i)=(int)(n)-1;i>=(int)(m);--i)
#define REP(i,n) rep(i,0,n)
#define REP2(i,n) rep2(i,0,n)
#define FOR(i,c) for(decltype((c).begin())i=(c).begin();i!=(c).end();++i)
#define all(hoge) (hoge).begin(),(hoge).end()
#define en '\n'
using ll = long long;
using ull = unsigned long long;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;
typedef pair<ll, ll> P;
constexpr long long INF = 1LL << 60;
constexpr int INF_INT = 1 << 25;
constexpr long long MOD = (ll) 1e9 + 7;
//constexpr long long MOD = 998244353LL;
using ld=long double;
static const ld pi = 3.141592653589793L;
typedef vector<ll> Array;
typedef vector<Array> Matrix;


template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

struct Edge {
	ll to, rev;
    long double cap;
	Edge(ll _to, long double _cap, ll _rev) {
	to = _to; cap = _cap; rev = _rev;
	}
};
using Edges = vector<Edge>;
using Graph = vector<Edges>;

void add_edge(Graph& G, ll from, ll to, long double cap, bool revFlag, long double revCap) {
	G[from].push_back(Edge(to, cap, (ll)G[to].size()));
	if (revFlag)G[to].push_back(Edge(from, revCap, (ll)G[from].size() - 1));
}

template< int mod >
struct ModInt {
  int x;

  ModInt() : x(0) {}

  ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

  ModInt &operator+=(const ModInt &p) {
    if((x += p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator-=(const ModInt &p) {
    if((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator*=(const ModInt &p) {
    x = (int) (1LL * x * p.x % mod);
    return *this;
  }

  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }

  ModInt operator-() const { return ModInt(-x); }

  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

  bool operator==(const ModInt &p) const { return x == p.x; }

  bool operator!=(const ModInt &p) const { return x != p.x; }

  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }

  ModInt pow(int64_t n) const {
    ModInt ret(1), mul(x);
    while(n > 0) {
      if(n & 1) ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }

  friend ostream &operator<<(ostream &os, const ModInt &p) {
    return os << p.x;
  }

  friend istream &operator>>(istream &is, ModInt &a) {
    int64_t t;
    is >> t;
    a = ModInt< mod >(t);
    return (is);
  }

  static int get_mod() { return mod; }
};

using mint = ModInt<MOD>;

void solve(){
    ll n;
    cin>>n;
    Graph g(n);
    REP(i,n-1){
        ll a,b;
        cin>>a>>b;
        a--;b--;
        add_edge(g,a,b,1,true,1);
    }

    vec<mint> con(n+1,0);
    con[2]=1;
    rep(i,1,n-1) con[i+2]=con[i]*(i+1);

    vec<vvec<mint>> dp(n);
    vec<ll> sz(n,1);
    auto dfs=[&](auto &&self,int v,int p)->void{
        dp[v] = vvec<mint>({{0,0},{1,0}});
        for(auto e:g[v]){
            if(e.to==p) continue;
            self(self,e.to,v);
            vvec<mint> dp2(sz[v]+sz[e.to]+1,vec<mint>(2,0));
            REP(i,dp[v].size()){
                REP(j,dp[e.to].size()){
                    REP(ip,2){
                        REP(jp,2){
                            dp2[i+j][(ip+jp)%2] += dp[v][i][ip] * dp[e.to][j][jp];
                            dp2[i][(ip+jp+1)%2] += dp[v][i][ip] * dp[e.to][j][jp] * con[j];//この辺でカットする時
                        }
                    }
                }
            }
            dp[v]=dp2;
            sz[v]+=sz[e.to];
        }
    };
    
    dfs(dfs,0,-1);
    mint ans=0;
    REP(i,dp[0].size()){
        ans+=dp[0][i][0]*con[i];
        ans-=dp[0][i][1]*con[i];
    }
    cout<<ans<<en;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    
    solve();
    //ll t;cin>>t;REP(i,t) solve();

    return 0;
}


Measured memory_bytes: 481280