#include<bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); ++i)
#define R(i, j, k) for(int i = (j); i >= (k); --i)
#define ll long long
#define vi vector <int>
#define sz(a) ((int) (a).size())
#define me(f, x) memset(f, x, sizeof(f))
#define uint unsigned int
#define ull unsigned long long 
#define i128 __int128
using namespace std;
const int N = 307, S = 5e7, mod = 1e9 + 7;
int n;
int qpow(int x, int y = mod - 2) {
	int res = 1;
	for(; y; x = (ll) x * x % mod, y >>= 1) if(y & 1) res = (ll) res * x % mod;
	return res;
}
int fac[N], ifac[N], inv[N];
void init(int x) {
	fac[0] = ifac[0] = inv[1] = 1;
	L(i, 2, x) inv[i] = (ll) (mod - mod / i) * inv[mod % i] % mod;
	L(i, 1, x) fac[i] = (ll) fac[i - 1] * i % mod, ifac[i] = (ll) ifac[i - 1] * inv[i] % mod;
} 
int C(int x, int y) {
	return x < y || y < 0 ? 0 : (ll) fac[x] * ifac[y] % mod * ifac[x - y] % mod;
}
inline int sgn(int x) {
	return (x & 1) ? mod - 1 : 1;
}

vi e[N];
int rt;
int su[N], sv[N], P[N][2];
int dist[N][N];
void dfs(int x, int fa) {
	for(auto&v : e[x]) if(v != fa) 
		dist[rt][v] = dist[rt][x] + 1, dfs(v, x);
}

int SZ[N][N][2];
int *dp[N][N][N], pool[S], *cur = pool;
int ei[N][N];

int disc[N][N];
int *hs[N][N][2][N];
int main () {
	ios :: sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	cin >> n;
	init(n + 1);
	if(n == 1) {
		cout << 1 << '\n';
		return 0;
	}
	L(i, 1, n - 1) {
		int u, v;
		cin >> u >> v;
		P[i][0] = u, P[i][1] = v;
		ei[u][v] = ei[v][u] = i;
		su[i] = u, sv[i] = v;
		e[u].emplace_back(v);
		e[v].emplace_back(u);
	} 
	L(i, 1, n) {
		L(j, 1, n) {
			disc[i][dist[i][j]] += 1;
		}
	}
	for(rt = 1; rt <= n; ++rt) 
		dfs(rt, 0);
	
	int mx = 0;
	L(i, 1, n) 
		L(j, 1, n) 
			mx = max(mx, dist[i][j]);
	L(i, 1, n - 1) {
		L(d, 0, mx / 2) {
			L(o, 0, 1)
				L(x, 1, n) 
					if(dist[P[i][o]][x] == d && dist[P[i][o ^ 1]][x] == d + 1) 
						SZ[d][i][o] += 1;
		}
	}
	L(e, 1, n - 1) {
		L(d, 0, n / 2) {
			L(i, 0, SZ[d][e][0]) 
				dp[d][e][i] = cur, cur += SZ[d][e][1] + 1;
			L(o, 0, 1) if(d) {
				L(i, 0, SZ[d - 1][e][o]) {
					hs[d][e][o][i] = cur, cur += SZ[d][e][o ^ 1] + 1;
				}
			}
		}
	}
	L(i, 1, n - 1) 
		dp[0][i][1][1] = 2;
	L(d, 1, mx / 2) {
		L(e, 1, n - 1) {
			int u = su[e];
			int v = sv[e];
			
			L(i, 0, SZ[d - 1][e][0])
				L(j, 0, SZ[d - 1][e][1]) if(dp[d - 1][e][i][j]) {
					int vl = dp[d - 1][e][i][j];
					if(i == SZ[d - 1][e][0]) {
						for(auto&t : ::e[u]) {
							int E = ei[u][t];
							int op = P[E][1] == t;
							if(t != v && SZ[d - 1][E][op] > 0) {
								(hs[d][E][op][1][j] += (ll) vl * SZ[d - 1][E][op] % mod) %= mod;
								int hr = SZ[d][e][0] - SZ[d - 1][E][op];
								if(hr) (hs[d][E][op][0][j + 1] += (ll) vl * hr % mod) %= mod;
							}
							if(t == v && SZ[d - 1][E][op] > 0) {
								(hs[d][E][op][j][1] += (ll) vl * SZ[d][E][op ^ 1] % mod) %= mod;
							}
						}
					}
					if(j == SZ[d - 1][e][1]) {
						for(auto&t : ::e[v]) {
							int E = ei[v][t];
							int op = P[E][1] == t;
							if(t != u && SZ[d - 1][E][op] > 0) {
								(hs[d][E][op][1][i] += (ll) vl * SZ[d - 1][E][op] % mod) %= mod;
								int hr = SZ[d][e][1] - SZ[d - 1][E][op];
								if(hr) (hs[d][E][op][0][i + 1] += (ll) vl * hr % mod) %= mod;
							}
							if(t == u && SZ[d - 1][E][op] > 0) {
								(hs[d][E][op][i][1] += (ll) vl * SZ[d][E][op ^ 1] % mod) %= mod;
							}
						}
					}
				}
		}
		L(e, 1, n - 1) L(o, 0, 1) {
			int lv = SZ[d - 1][e][o], rv = SZ[d][e][o ^ 1];
			L(i, 0, lv) {
				L(j, 0, rv) if(hs[d][e][o][i][j]) {
					if(i < lv) 
						(hs[d][e][o][i + 1][j] += (ll)hs[d][e][o][i][j] * (lv - i) % mod) %= mod;
					if(j < rv) 
						(hs[d][e][o][i][j + 1] += (ll)hs[d][e][o][i][j] * (rv - j) % mod) %= mod;
				}
			}
		}
		L(e, 1, n - 1) L(o, 0, 1) if(SZ[d][e][o]) {
			int lv = SZ[d - 1][e][o], rv = SZ[d][e][o ^ 1];
			L(j, 0, rv) if(hs[d][e][o][lv][j]) {
				int mv = (ll) hs[d][e][o][lv][j] * SZ[d][e][o] % mod;
				if(!o) {
					(dp[d][e][1][j] += mv) %= mod;
				} else {
					(dp[d][e][j][1] += mv) %= mod;
				}
			}
		}
		
		L(e, 1, n - 1) {
			int lv = SZ[d][e][0], rv = SZ[d][e][1];
			L(i, 0, lv) {
				L(j, 0, rv) if(dp[d][e][i][j]) {
					if(i < lv) 
						(dp[d][e][i + 1][j] += (ll)dp[d][e][i][j] * (lv - i) % mod) %= mod;
					if(j < rv) 
						(dp[d][e][i][j + 1] += (ll)dp[d][e][i][j] * (rv - j) % mod) %= mod;
				}
			}
		}
//		L(e, 1, n - 1) {
//			int lv = SZ[d][e][0], rv = SZ[d][e][1];
//			L(i, 0, lv) {
//				L(j, 0, rv) if(dp[d][e][i][j]) {
//					cout << P[e][0] << ' ' << P[e][1] << ", " << d << " with " 
//						<< i << ' ' << j << " : " << dp[d][e][i][j] << endl;
//				}
//			}
//		}
	}
	
	if(mx & 1) {
		int gen = mx / 2;
		int ans = 0;
		L(i, 1, n - 1) 
			(ans += dp[gen][i][SZ[gen][i][0]][SZ[gen][i][1]]) %= mod;
		cout << ans << '\n';
	} else {
		int gen = (mx - 1) / 2;
		int ans = 0;
		L(e, 1, n - 1) {
			int lv = SZ[gen][e][0];
			int rv = SZ[gen][e][1];
			L(i, 0, lv) {
				L(j, 0, rv) if(dp[gen][e][i][j]) {
					int vl = dp[gen][e][i][j];
					if(SZ[gen + 1][e][0] && i == lv) {
						(ans += (ll) fac[SZ[gen + 1][e][0] + rv - j - 1] * vl % mod) %= mod;
					} 
					if(SZ[gen + 1][e][1] && j == rv) {
						(ans += (ll) fac[SZ[gen + 1][e][1] + lv - i - 1] * vl % mod) %= mod;
					} 
				}
			}
		}
		cout << ans << '\n';
	}
	return 0;
}