// what is matter? never mind. 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
#define ull unsigned long long
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}
 
#define mod 1000000007
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}

modint C[605][605];

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 2000005
#define inf 0x3f3f3f3f

int n,m;
vi e[maxn];
modint f[605][305][305],g[605][305][305];
// what edge, diameter, rest cnt

int u[605],v[605];
int cnt[605][305];
int id[305][305];
void dfs(int u,int pa,int d,int*c){
	++c[d];
	for(auto v:e[u])if(v!=pa)dfs(v,u,d+1,c);
}

int s,t,mx,par[maxn],d[maxn],len;
void dfs(int u,int pa,int d){
	par[u]=pa;
	if(d>mx)mx=d,t=u;
	for(auto v:e[u])if(v!=pa)dfs(v,u,d+1);
}
void find(){
	s=1,t=1,mx=0,dfs(1,0,0);
	s=t,mx=0,dfs(s,0,0);
	for(int u=t;u;u=par[u]) d[++len]=u;
}

signed main()
{
	n=read();
	initC(305);
	For(i,0,300){
		C[i][0]=1;
		For(j,1,i)C[i][j]=C[i-1][j]+C[i-1][j-1];
	}
	For(i,2,n){
		int u=read(),v=read();
		e[u].pb(v);
		::u[(i-1)*2-1]=u,::v[(i-1)*2-1]=v;
		e[v].pb(u);
		::u[(i-1)*2]=v,::v[(i-1)*2]=u;
	}
	m=(n-1)*2;
	For(i,1,m){
		id[u[i]][v[i]]=i;
		dfs(v[i],u[i],0,cnt[i]);
	}
	find();
	if(len%2==0){
		int u=d[len/2],v=d[len/2+1];
		int t=cnt[id[v][u]][len/2-1];
		f[len-2][id[u][v]][t]=fac[t];
		t=cnt[id[u][v]][len/2-1];
		f[len-2][id[v][u]][t]=fac[t];
	}else{
		int u=d[len/2+1];
	//	cout<<"u: "<<u<<"\n";
		for(auto v:e[u]){
			int t=cnt[id[v][u]][len/2];
		//	cout<<"u,v "<<v<<" "<<len-1<<" "<<id[u][v]<<" "<<t<<" "<<fac[t].x<<"\n";
			g[len-2][id[u][v]][t]=fac[t];
		}
	}
	Rep(i,len-1,1) For(j,1,m) For(k,1,n) {
		int u=::u[j],v=::v[j];
		if(f[i][j][k].x){
		//	cout<<"f: "<<i<<" "<<j<<" "<<k<<" "<<f[i][j][k].x<<"\n";
			// point, from u-->v, now is v
			int t=cnt[id[u][v]][i/2];
			For(x,1,t) g[i-1][id[v][u]][x]+=f[i][j][k]*fac[t]*C[k-1+t-x][t-x];
			for(auto w:e[v]){
				if(u==w) continue;
				if(!cnt[id[v][w]][i/2-1]) continue;
				// k before tu
				int tu=cnt[id[v][u]][i/2-1];
				int tt=cnt[id[u][v]][i/2]-cnt[id[v][w]][i/2-1];
				g[i-1][id[v][w]][k+tu+tt]+=f[i][j][k]*fac[tu]*fac[tt]*C[k+tu+tt][tt];
			}
		}
		if(g[i][j][k].x){
		//	cout<<"g: "<<i<<" "<<j<<" "<<k<<" "<<g[i][j][k].x<<"\n";
			// edge
			int t=cnt[id[v][u]][i/2];
			f[i-1][id[u][v]][k+t]+=fac[t]*g[i][j][k];
			t=cnt[id[u][v]][i/2];
			For(x,1,t) f[i-1][id[v][u]][x]+=g[i][j][k]*fac[t]*C[k-1+t-x][t-x];
		}
	}
	modint res=0;
	For(j,1,m) For(k,1,n) res+=f[0][j][k];
	cout<<res.x;
	return 0;
}
/*

*/