func_code_string:    // Problem : B. Tree Array   // Contest : Codeforces - Codeforces Round #728 (Div. 1)   // URL : https://codeforces.com/contest/1540/problem/B   // Memory Limit : 256 MB   // Time Limit : 2000 ms   // Powered by CP Editor (https://github.com/cpeditor/cpeditor)      #include <bits/stdc++.h>      using namespace std;      int N;   long long pas[205][205];   const long long MOD = 1e9+7;   long long cache[205][205];   vector<int> graph[205];   int par[205];   bool vis[205];      long long add(long long a, long long b){    return (a + b) % MOD;   }      long long mult(long long a, long long b){    return a * b % MOD;   }      long long qikpow(long long b, long long e){    if(!e){     return 1;    }    long long ret = qikpow(b, e / 2);    ret = mult(ret, ret);    if(e & 1){     ret = mult(ret, b);    }    return ret;   }      long long sub(long long a, long long b){    return ((a - b) % MOD + MOD ) % MOD;   }      long long divd(long long a, long long b){    return mult(a, qikpow(b, MOD - 2));   }      void dfs1(int n){    for(int e : graph[n]){     if(e != par[n]){      par[e] = n;      dfs1(e);     }    }   }      int dfs2(int n, int p){    int sz = 1;    for(int e : graph[n]){     if(!vis[e] && p != e){      sz += dfs2(e, n);     }    }    return sz;   }      int main(){    ios::sync_with_stdio(0);    cin.tie(0);    cout.tie(0);    cin >> N;    for(int i = 0; i <= N; i++){     pas[i][0] = 1;     for(int j = 1; j <= i; j++){      pas[i][j] = add(pas[i-1][j], pas[i-1][j-1]);     }    }     for(int i = 1; i < N; i++){     int a, b;     cin >> a >> b;     graph[a].emplace_back(b);     graph[b].emplace_back(a);    }    long long ans = 0;    for(int n = 1; n <= N; n++){     fill(par, par+1+N, 0);     dfs1(n);     vis[n] = 1;     for(int k = n+1; k <= N; k++){      int cur = k, len = 0;      while(cur != n){       vis[cur] = 1;       len++;       cur = par[cur];      }      cur = k;      for(int t = len; t; t--){       int s = dfs2(cur, 0);       //cout << s <<   n ;       long long tot = divd(s, N);       if(t == len){        ans = add(ans, tot);       }       else{        /*        long long p = 1;//qikpow(divd(1, 2), len);             cout << p <<     << pas[len - 1][len - t] <<   n ;        p = mult(p, divd(pas[len - 1][len - t], pas[len][len-t]));        cout << n <<     << k <<     << cur <<   n ;        cout << p <<     << tot <<   n ;        ans = add(ans, mult(p, tot));        */        //cout << n <<     << k <<     << cur <<   n ;        //cout << tot <<   n ;        if(!cache[len][t]){         for(int c = 0; c < t; c++){          cache[len][t] = add(cache[len][t], mult(pas[c+len-t-1][len-t-1], qikpow(divd(1, 2), c+len-t)));          //cout << mult(mult(pas[c+len-t-1][len-t-1], qikpow(divd(1, 2), c+len-t)), tot) <<   n ;         }          }        ans = add(mult(tot, cache[len][t]), ans);               }       cur = par[cur];      }      cur = k;      while(cur != n){       vis[cur] = 0;       cur = par[cur];      }     }     vis[n] = 0;    }    cout << ans;   }