#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const int N = 211;
const int mod = 1e9 + 7;

int g[N][N], n;
ll p[N][N], ans = 0;

ll qpow(ll a, ll b) {
	ll ans = 1;
	while (b) {
		if (b & 1) ans = ans * a % mod;
		a = a * a % mod;
		b >>= 1;
	}
	return ans;
}


int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) 
		for (int j = 1; j <= n; ++j) 
			if (i != j)
				g[i][j] = n << 1;
	for (int i = 0, u, v; i < n - 1; ++i) {
		scanf("%d%d", &u, &v);
		g[u][v] = g[v][u] = 1;
	}
	ll inv2 = qpow(2, mod - 2);
	ll invn = qpow(n, mod - 2);
	for (int k = 1; k <= n; ++k) {
		for (int i = 1; i <= n; ++i) {
			for (int j = 1; j <= n; ++j)
				g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
		}
	}
	for (int i = 1; i <= n; ++i) 
		p[i][0] = 1;
	for (int i = 1; i <= n; ++i) 
		for (int j = 1; j <= n; ++j)
			p[i][j] = inv2 * (p[i - 1][j] + p[i][j - 1]) % mod;

	for (int i = 1; i <= n; ++i) {
		for (int j = i + 1; j <= n; ++j) {
			for (int k = 1; k <= n; ++k) {
				int x = (g[i][j] + g[i][k] - g[j][k]) >> 1;
				ans = (ans + p[x][g[i][j] - x]) % mod;
			}
		}
	}
	ans = ans * invn % mod;
	printf("%lld\n", ans);

}