#include <iostream>
#include <cstdio>
const int nn = 205;
const int mod = 1e9 + 7;
int add(int a, int b) {
	return a + b >= mod ? a + b - mod : a + b;
}
int cnt, prev[nn << 1], last[nn], to[nn << 1];
void addedge(int p, int q) {
	prev[++cnt] = last[p];
	to[last[p] = cnt] = q;
}
int list[10][nn << 1], dep[nn], pt, id[nn];
int max(int p, int q) {
	return dep[p] < dep[q] ? p : q;
}
void dfs(int p, int fa) {
	dep[p] = dep[fa] + 1;
	list[0][++pt] = p;
	id[p] = pt;
	for (int i = last[p], q; i; i = prev[i]) {
		if ((q = to[i]) != fa) {
			dfs(q, p);
			list[0][++pt] = p;
		}
	}
}
int log[nn << 1];
void init() {
	for (int j = 1; (1 << j) <= pt; j++)
		for (int i = 1; i + (1 << j) <= pt; i++)
			list[j][i] = max(list[j - 1][i], list[j - 1][i + (1 << j - 1)]);
	log[0] = -1;
	for (int i = 1; i <= pt; i++) log[i] = log[i >> 1] + 1;
}
int lca(int p, int q) {
	int l = id[p], r = id[q];
	if (l > r) std::swap(l, r);
	int tmp = log[r - l + 1];
	return max(list[tmp][l], list[tmp][r - (1 << tmp) + 1]);
}
int n, ans, f[nn][nn], inv[nn << 1], c[nn << 1][nn << 1], inv2[nn << 1];
int main() {
	scanf("%d", &n);
	for (int i = 1, p, q; i < n; i++) {
		scanf("%d %d", &p, &q);
		addedge(p, q);
		addedge(q, p);
	}
	inv2[0] = inv[1] = 1; inv2[1] = mod + 1 >> 1;
	for (int i = 2; i <= n << 1; i++) {
		inv[i] = 1ll * inv[mod % i] * (mod - mod / i) % mod;
		inv2[i] = 1ll * inv2[i - 1] * inv[2] % mod;
	}
	c[0][0] = 1;
	for (int i = 1; i <= n << 1; i++) {
		c[i][0] = 1;
		for (int j = 1; j <= n << 1; j++)
			c[i][j] = add(c[i - 1][j - 1], c[i - 1][j]);
	}
	for (int i = 0; i <= n; i++) {
		for (int j = 0; j <= n; j++) {
			for (int k = i; k < i + j; k++) {
				if (k) f[i][j] = add(f[i][j], 1ll * (c[k][i] - c[k - 1][i] + mod) * inv2[k] % mod);
				else f[i][j] = add(f[i][j], 1ll * c[k][i] * inv2[k] % mod);
			}
		}
	}
	for (int p = 1; p <= n; p++) {
		pt = 0; dfs(p, 0); init();
		for (int i = n; i >= 1; i--) {
			for (int j = 1; j < i; j++) {
				int dl = dep[lca(i, j)];
				ans = add(ans, f[dep[i] - dl][dep[j] - dl]);
			}
		}
	}
	printf("%lld", 1ll * ans * inv[n] % mod);
}