#include<iostream>
#include<cstdio>
#include<vector>
#define N 80
#define mod 1000000007
using namespace std;
int read()
{
    char c=0;
    int sum=0;
    while (c<'0'||c>'9') c=getchar();
    while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
    return sum;
}
int MD(int x)
{
    return x>=mod?x-mod:x;
}
void Adder(int &x,int d)
{
    x+=d;
    if (x>=mod) x-=mod;
    return;
}
void Adder2(int &x,int d)
{
    x+=d;
    if (x<0) x+=mod;
    return;
}
int fast_pow(int a,int b)
{
    int res=1,mul=a;
    while (b)
    {
	if (b&1) res=1ll*res*mul%mod;
	mul=1ll*mul*mul%mod,b>>=1;
    }
    return res;
}
int n,ans,sz[N+1],fac[N+1],invfac[N+1],C[N+1][N+1],dp[N+1][N+1],dsp[N+1],DP[N+1][N+1][N+1];
bool used[N+1];
vector<int>E[N+1];
void add(int x,int y)
{
    E[x].push_back(y),E[y].push_back(x);
    return;
}
void dfs(int x)
{
    int res,rst=1;
    vector<int>p;
    used[x]=sz[x]=dp[x][0]=1;
    for (int i=0;i<E[x].size();++i)
	if (!used[E[x][i]])
	    dfs(E[x][i]),p.push_back(E[x][i]),rst+=sz[E[x][i]];
    p.push_back(x);
    for (int i=0;i<=rst;++i) dsp[i]=0;
    for (int i=1;i<=p.size();++i)
	for (int j=0;j<=sz[p[i-1]];++j)
	{
	    res=0;
	    for (int k=0;k<=p.size();++k)
		for (int s=0;s<=rst;++s)
		    for (int t=0;t<=rst;++t)
			DP[k][s][t]=0;
	    DP[0][0][0]=1;
	    for (int k=1;k<=p.size();++k)
	    {
		if (k==i)
		{
		    for (int s=0;s<=res;++s)
			for (int t=s;t<=res;++t)
			{
			    for (int s2=1;s2<=sz[p[k-1]]-j;++s2)
				for (int t2=s2;t2<=sz[p[k-1]]-j;++t2)
				    Adder(DP[k][s+s2][t+t2],1ll*DP[k-1][s][t]*C[sz[p[k-1]]-j][t2]%mod*C[t2-1][s2-1]%mod*invfac[s2-1]%mod*fac[t2]%mod);
			}
		    res+=sz[p[k-1]]-j;
		}
		else
		{
		    for (int s=0;s<=res;++s)
			for (int t=s;t<=res;++t)
			{
			    for (int s2=1;s2<=sz[p[k-1]];++s2)
				for (int t2=s2;t2<=sz[p[k-1]];++t2)
				    Adder(DP[k][s+s2][t+t2],1ll*DP[k-1][s][t]*C[sz[p[k-1]]][t2]%mod*C[t2-1][s2-1]%mod*invfac[s2]%mod*fac[t2]%mod);
			    Adder(DP[k][s][t],DP[k-1][s][t]);
			}
		    res+=sz[p[k-1]];
		}
	    }
	    for (int s=1;s<=res;++s)
		for (int t=s;t<=res;++t)
		{
		    if (!((t-s)&1)) Adder(dsp[t+j],1ll*dp[p[i-1]][j]*DP[p.size()][s][t]%mod*fac[s-1]%mod);
		    else Adder2(dsp[t+j],-1ll*dp[p[i-1]][j]*DP[p.size()][s][t]*fac[s-1]%mod);
		}
	}
    sz[x]=rst;
    for (int i=0;i<=rst;++i) Adder(dp[x][i],dsp[i]);
    return;
}
int main()
{
    int x,y;
    fac[0]=1;
    for (int i=1;i<=N;++i) fac[i]=1ll*fac[i-1]*i%mod;
    invfac[N]=fast_pow(fac[N],mod-2);
    for (int i=N-1;i>=0;--i) invfac[i]=1ll*invfac[i+1]*(i+1)%mod;
    for (int i=0;i<=N;++i) C[i][0]=1;
    for (int i=1;i<=N;++i)
	for (int j=1;j<=i;++j)
	    C[i][j]=MD(C[i-1][j-1]+C[i-1][j]);
    n=read();
    for (int i=1;i<=n-1;++i) x=read(),y=read(),add(x,y);
    dfs(1),printf("%d\n",dp[1][n]);
    return 0;
}