// MagicDark
#include <bits/stdc++.h>
#define debug cerr << "\033[32m[" << __LINE__ << "]\033[0m "
#define SZ(x) ((int) x.size() - 1)
#define all(x) x.begin(), x.end()
#define ms(x, y) memset(x, y, sizeof x)
#define F(i, x, y) for (int i = (x); i <= (y); i++)
#define DF(i, x, y) for (int i = (x); i >= (y); i--)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
template <typename T> T& chkmax(T& x, T y) {return x = max(x, y);}
template <typename T> T& chkmin(T& x, T y) {return x = min(x, y);}
template <typename T> T& read(T &x) {
	x = 0; int f = 1; char c = getchar();
	for (; !isdigit(c); c = getchar()) if (c == '-') f = - f;
	for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
	return x *= f;
}
const int N = 5010, MOD = 1e9 + 7;
inline int& add(int &x, ll y) {return x = (x + y) % MOD;}
int n, x[N], y[N], cnt, d[N][N], mx, c, fa[N], e[N][N], f[2][N][N], ans, C[N][N], g[N][N];
vector <int> v[N];
int fac[N], ifac[N], inv[N];
inline void binom(int x) {
	fac[0] = ifac[0] = inv[1] = 1;
	F(i, 2, x) inv[i] = (ll) (MOD - MOD / i) * inv[MOD % i] % MOD;
	F(i, 1, x) fac[i] = (ll) fac[i - 1] * i % MOD, ifac[i] = (ll) ifac[i - 1] * inv[i] % MOD;
	F(i, 0, x) {
		C[i][0] = 1;
		F(j, 1, i) C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % MOD;
	}
}
// inline int C(int x, int y) {return x < y || y < 0 ? 0 : (ll) fac[x] * ifac[y] % MOD * ifac[x - y] % MOD;}
void dfs(int id, int x, int fa, int dep) {
	// debug << x << " " << id << " " << dep << endl;
	::fa[x] = fa;
	if (dep + 1 > mx) {
		mx = dep + 1;
		int w = x;
		F(i, 1, mx >> 1) w = ::fa[w];
		if (mx & 1) c = e[w][::fa[w]];
		else c = w;
	}
	d[id][dep]++;
	for (int i: v[x])
		if (i != fa) dfs(id, i, x, dep + 1);
}
signed main() {
	binom(read(n));
	F(i, 1, n - 1) {
		y[i << 1 | 1] = read(x[i << 1]), x[i << 1 | 1] = read(y[i << 1]);
		e[x[i << 1]][y[i << 1]] = i << 1;
		e[y[i << 1]][x[i << 1]] = i << 1 ^ 1;
		v[x[i << 1]].push_back(y[i << 1]);
		v[y[i << 1]].push_back(x[i << 1]);
	}
	F(i, 2, 2 * n - 1) dfs(i, y[i], x[i], 0);
	// debug << mx << " " << c << endl;
	if (mx & 1) {
		int a = d[c][mx >> 1], b = d[c ^ 1][mx >> 1];
		F(i, 0, a - 1) f[mx & 1 ^ 1][c][i] = (ll) fac[b] * C[i + b - 1][i] % MOD;
		F(i, 0, b - 1) f[mx & 1 ^ 1][c ^ 1][i] = (ll) fac[a] * C[i + a - 1][i] % MOD;
	} else {
		for (int i: v[c]) {
			int a = d[e[c][i]][(mx >> 1) - 1], b = d[e[c][i] ^ 1][mx >> 1];
			// debug << a << " " << b << endl;
			// debug << e[c][i] << endl;
			F(j, 0, a - 1) f[mx & 1 ^ 1][e[c][i]][j] = (ll) fac[b] * C[j + b - 1][j] % MOD;
		}
	}
	DF(i, mx - 1, 1) {
		int cur = i & 1, to = cur ^ 1;
		if (i & 1) {
			F(j, 2, n * 2 - 1) {
				int a = d[j][i >> 1], b = d[j ^ 1][i >> 1];
				if (!a || !b) continue;
				F(k, 0, a - 1) {
					g[k][0] = ((k ? g[k - 1][0] : 0) + f[cur][j][k]) % MOD;
					// if (f[cur][j][k]) debug << i << ' ' << j << " " << k << " " << f[cur][j][k] << endl;
					f[cur][j][k] = 0;
					F(l, 1, b - 1) g[k][l] = (g[k][l - 1] + (k ? g[k - 1][l] : 0)) % MOD;
					add(f[to][j][k], (ll) g[k][b - 1] * fac[b]);
					// F(l, 0, b - 1) add(f[to][j ^ 1][l], (ll) f[cur][j][k] * C[a - k - 1 + l][l] % MOD * fac[b]);
				}
				F(k, 0, b - 1) add(f[to][j ^ 1][k], (ll) g[a - 1][k] * fac[a]);
			}
		} else {
			F(j, 2, n * 2 - 1) {
				int a = d[j][i >> 1], b = d[j ^ 1][(i >> 1) - 1];
				if (!a || !b) continue;
				// debug << i << " " << j << " " << a << " " << b << endl;
				F(k, 0, a - 1) {
					// if (f[cur][j][k] != 1 || k) f[cur][j][k] = 0;
					g[k][0] = ((k ? g[k - 1][0] : 0) + f[cur][j][k]) % MOD;
					// if (f[cur][j][k]) debug << i << ' ' << j << " " << k << " " << f[cur][j][k] << endl;
					f[cur][j][k] = 0;
					F(l, 1, b) g[k][l] = (g[k][l - 1] + (k ? g[k - 1][l] : 0)) % MOD;
				}
				// debug << i << " " << j << endl;
				F(k, 0, b - 1) add(f[to][j ^ 1][k], (ll) g[a - 1][k] * fac[a]);//, debug << "! " << k << " " << g[a - 1][k] << " " << fac[a] << endl;
				// continue;
				// debug << y[j] << endl;
				for (int k: v[y[j]]) {
					int c = d[e[y[j]][k]][(i >> 1) - 1];
					if (k != x[j] && c) {
						F(l, 0, c - 1) {
							add(f[to][e[y[j]][k]][l], (ll) g[a - c + l][b - 1] * C[a - c + l][l] % MOD * fac[b] % MOD * fac[a - c]);
							if (a - c + l) add(f[to][e[y[j]][k]][l], (ll) g[a - c + l - 1][b] * C[a - c + l - 1][l] * fac[b] % MOD * fac[a - c]);
						}
					}
				}
			}
		}
	}
	F(i, 2, n * 2 - 1) add(ans, f[0][i][0]);
	cout << ans;
	return 0;
}
/* why?
*/