#include<bits/stdc++.h>
#define ll long long
#define db double
#define ull unsigned long long
#define pb push_back
#define pii pair<int, int>
#define FR first
#define SE second
using namespace std;
inline int read() {
  int x = 0; bool op = false;
  char c = getchar();
  while(!isdigit(c))op |= (c == '-'), c = getchar();
  while(isdigit(c))x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
  return op ? -x : x;
}
const int N = 110;
const int P = 1e9 + 7;
void add(int &a, int b) {a += b; a >= P ? a -= P : 0;}
void sub(int &a, int b) {a -= b; a < 0 ? a += P : 0;}
int ksm(int x, int k) {
  int res = 1;
  for(int pw = x; k; (k & 1) ? res = 1ll * res * pw % P : 0, pw = 1ll * pw * pw % P, k >>= 1);
  return res;
}
int fac[N], ifac[N];
void init() {
  fac[0] = ifac[0] = 1;
  for(int i = 1; i < N; i++)fac[i] = 1ll * fac[i - 1] * i % P;
  ifac[N - 1] = ksm(fac[N - 1], P - 2);
  for(int i = N - 2; i; i--)ifac[i] = 1ll * ifac[i + 1] * (i + 1) % P;
  return ;
}
int com(int n, int m) {return n < m || m < 0 ? 0 : 1ll * fac[n] * ifac[m] % P * ifac[n - m] % P;}
int n, ans;
vector<int> G[N];
int sz[N];
void dfs1(int u, int fa) {
  sz[u] = 1;
  for(int v : G[u])if(v != fa)
    dfs1(v, u), sz[u] += sz[v];
  return ;
}
int g[N][N], f[N][N];
int calc(int u, int fa, int tar) {
  int sum = 0;
  g[0][1] = g[1][0] = 1; sum = 1;
  for(int v : G[u]) {
    if(v == fa || v == tar)continue;
    for(int i = sum; ~i; i--) {
      for(int j = sum; ~j; j--) {
        int val = g[i][j]; g[i][j] = 0;
        for(int x = 0; x <= sz[v]; x++) {
          int t = sz[v] - x;
          for(int y = 0; y < max(1, t); y++) {
            int c = t - y, sgn = (y & 1) ? P - 1 : 1;
            int coef = 1ll * com(sz[v], x) * fac[t] % P * ifac[c] % P * com(max(0, t - 1), y) % P;
            add(g[i + x][j + c], 1ll * sgn * coef % P * val % P);
            // if(val)cout << "trans:" << i << ' ' << j << ' ' << x << ' ' << v << ' ' << y << ' ' << sz[v] << ' ' << x << endl;
          }
        }
      }
    }
    sum += sz[v];
    // if(tar == 0) {
    //   printf("e:%d %d\n", u, v);
    //   for(int i = 0; i <= sum; i++) {
    //     for(int j = 0; j <= sum; j++) {
    //       printf("%d %d %d\n", i, j, g[i][j]);
    //     }
    //   }
    // }
  }
  return sum;
}
void init(int sum) {
  for(int i = 0; i <= sum; i++) {
    for(int j = 0; j <= sum; j++) {
      g[i][j] = 0;
    }
  }
  return ;
}
void DP(int u, int fa, int tar) {
  int sum = calc(u, fa, tar);
  for(int i = 0; i <= sum; i++) {
    for(int j = 0; j <= sum; j++) {
      for(int x = 0; x <= sz[tar]; x++) {
        for(int y = x; y <= sz[tar] - 2; y++) {
          int t = y - x;
          for(int z = 0; z <= t; z++) {
            int v = t - z, sgn = (z & 1) ? P - 1 : 1;
            int coef = 1ll * com(max(t - 1, 0), z) * ifac[v] % P * fac[j + v] % P;
            if(v)sub(coef, 1ll * com(max(t - 1, 0), z) * ifac[v - 1] % P * fac[j + v - 1] % P);
            coef = 1ll * coef * fac[i] % P * com(i + x, x) % P;
            add(f[tar][y], 1ll * sgn * coef % P * f[u][i + x] % P * g[i][j] % P);
          }
        }
      }
    }
  }
  init(sum);
  return ;
}
void calc_ans(int u, int fa) {
  // puts("calc_ans");
  int sum = calc(u, fa, 0);
  // puts("calc_ans");
  // printf("calc_ans:%d\n", u);
  for(int i = 0; i <= sum; i++) {
    for(int j = 0; j <= sum; j++) {
      // if(f[u][i])printf("g:%d %d %d\n", i, j, 1ll * g[i][j] * fac[i] % P * fac[j] % P);
      add(ans, 1ll * g[i][j] * f[u][i] % P * fac[i] % P * fac[j] % P);
    }
  }
  init(sum);
  return ;
}
void dfs2(int u, int fa) {
  calc_ans(u, fa);
  // printf("%d %d\n", u, ans);
  // for(int i = 0; i <= sz[u]; i++)printf("%d ", f[u][i]); putchar('\n');
  for(int v : G[u])if(v != fa)DP(u, fa, v);
  for(int v : G[u])if(v != fa)dfs2(v, u);
  return ;
}
int main() {
  init();
  n = read();
  for(int i = 1; i < n; i++) {
    int u = read(), v = read();
    G[u].pb(v); G[v].pb(u);
  }
  f[1][0] = 1;
  dfs1(1, 0); dfs2(1, 0);
  printf("%d\n", ans);
  return 0;
}