#include <bits/stdc++.h>
using namespace std;
#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifndef ONLINE_JUDGE
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
// debug & operator << (debug & dd, P p) { dd << ", " << p.x << ", " << p.y << ")"; return dd; }

#define ll long long
const ll mod = 1e9 + 7;

ll powM(ll a, ll b) {
    ll res = 1;
    ll base = 1;
    while(base <= b) {
        if(base & b) {
            res = res * a;
            res = res % mod;
            if(res < 0) {
                res = res + mod; 
            }
        }
        base = base * 2;
        a = a * a;
        a = a % mod;
        if(a < 0) {
            a = a + mod; 
        }
    }
    return res;
}

ll mod_inverse(ll n) {
    return powM(n, mod - 2);
}

int main() {
    ll n;
    cin >> n;
    // calculate dp.
    vector<vector<ll>> dp(205, vector<ll> (205));
    dp[0][0] = 0;
    for(ll i = 0; i < 205; ++i) {
        dp[0][i] = 1;
        dp[i][0] = 0;
    }
    for(ll i = 1; i < 205; ++i) {
        for(ll j = 1; j < 205; ++j) {
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            dp[i][j] = dp[i][j] % mod;
            dp[i][j] = dp[i][j] * mod_inverse(2);
            dp[i][j] = dp[i][j] % mod;
            if(dp[i][j] < 0) {
                dp[i][j] = dp[i][j] + mod;
            }
        }
    }
    // debug() << imie(dp);
    // read tree.
    vector<vector<ll>> graph(n, vector<ll> (n, 0));
    for(ll i = 0; i < n - 1; ++i) {
        ll x, y;
        cin >> x >> y;
        x--;
        y--;
        graph[x][y] = 1;
        graph[y][x] = 1;
    }
    // debug() << imie(graph);
    // floyd warshall.
    vector<vector<ll>> dist(n, vector<ll> (n, 800));
    for(ll i = 0; i < n; ++i) {
        dist[i][i] = 0;
    }
    for(ll i = 0; i < n; ++i) {
        for(ll j = 0; j < n; ++j) {
            if(graph[i][j]) {
                dist[i][j] = 1;
            }
        }
    }
    for(ll k = 0; k < n; ++k) {
        for(ll i = 0; i < n; ++i) {
            for(ll j = 0; j < n; ++j) {
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }
    // debug() << imie(dist);
    // calculate answer.
    ll ans = 0;
    for(ll i = 0; i < n; ++i) {
        for(ll j = i + 1; j < n; ++j) {
            for(ll k = 0; k < n; ++k) {
                ll dmin = dist[i][k];
                ll dmax = dist[j][k];
                ll t = (dmin + dmax - dist[i][j]) / 2;
                dmin = dmin - t;
                dmax = dmax - t;
                ans = ans + dp[dmax][dmin];
                ans = ans % mod;
                if(ans < 0) {
                    ans = ans + mod; 
                }
            }
        }
    }
    ans = (ans * mod_inverse(n) % mod);
    cout << ans << endl;
}