#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <algorithm>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#define repi(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i,a) repi(i,0,a)
#define repdi(i,a,b) for(ll i=(a)-1;i>=(b);--i)
#define repd(i,a) repdi(i,a,0)
#define itr(it,a) for( auto it = (a).begin(); it != (a).end(); ++it )
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

using ll = long long;
using P = std::pair<ll, ll>;

constexpr ll INF = 1ll<<60;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

template<class S, class T>
std::ostream& operator<< ( std::ostream& out, const std::pair<S,T>& a )
{ std::cout << '(' << a.first << ", " << a.second << ')'; return out; }

template<class T>
std::ostream &operator<< ( std::ostream& out, const std::vector<T>& a )
{ std::cout << '['; rep( i, a.size() ){ std::cout << a[i]; if( i != a.size()-1 ) std::cout << ", "; } std::cout << ']'; return out; }

const ll mod = 1000000007;

struct mint {
  ll x; // typedef long long ll;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  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) 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;
    if (t&1) a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const {
    return pow(mod-2);
  }
  mint& operator/=(const mint a) {
    return (*this) *= a.inv();
  }
  mint operator/(const mint a) const {
    mint res(*this);
    return res/=a;
  }
};

struct combination {
  std::vector<mint> fact, ifact;
  combination(int n):fact(n+1),ifact(n+1) {
    assert(n < mod);
    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];
  }
};

ll N;
std::vector<ll> G[5010];
mint dp[5010][5010][2];
mint dp2[2][5010][2];
ll subtree[5010];
mint two[5010];
combination comb( 10000 );

void dfs( ll v, ll p = -1 )
{
  subtree[v] = 1;

  for( auto u : G[v] ) if( u != p )
  {
    dfs( u, v );
    subtree[v] += subtree[u];
  }

  ll sum = 0, cnt = 0;
  
  rep( j, subtree[v]+1 ) rep( k, 2 )
      dp2[0][j][k] = dp2[1][j][k] = 0;

  dp2[0][0][0] = 1;

  for( auto u : G[v] ) if( u != p )
  {
    rep( j, subtree[v]+1 ) rep( k, 2 )
      dp2[(cnt+1)&1][j][k] = 0;

    rep( sz, subtree[u] ) rep( j, sum+1 ) rep( k, 2 ) rep( l, 2 )
    {
      dp2[(cnt+1)&1][j+sz+1][k^l] += dp2[cnt&1][j][k]*dp[u][sz][l];

      if( !((sz+1)&1) )
        dp2[(cnt+1)&1][j][k^l^1] += dp2[cnt&1][j][k]*dp[u][sz][l]*comb.fact[sz]*two[sz/2]*comb.ifact[sz/2];
    }

    sum += subtree[u];
    ++cnt;
  }

  rep( j, sum+1 ) rep( k, 2 )
  {
    //printf( "dp2[%lld][%lld] = %lld\n", j, k, dp2[cnt&1][j][k].x );

    if( !v && !((j+1)&1) )
      dp[v][0][k] += dp2[cnt&1][j][k]*comb.fact[j+1]*two[(j+1)/2]*comb.ifact[(j+1)/2];
    else
      dp[v][j][k] += dp2[cnt&1][j][k];
  }
}

int main()
{
  std::cin >> N;

  rep( i, N-1 )
  {
    ll x, y;
    std::cin >> x >> y;
    --x; --y;

    G[x].emplace_back( y );
    G[y].emplace_back( x );
  }

  two[N+5] = mint(2).pow(N+5).inv();

  repd( i, N+5 )
    two[i] = two[i+1]*2;

  dfs( 0 );

  mint ans = 0;

  rep( j, subtree[0]+1 )
    ans += dp[0][j][0]-dp[0][j][1];

  std::cout << ans.x << std::endl;

  return 0;
}

Measured memory_bytes: 393984