func_code_string: /*     */   #include <bits/stdc++.h>   using namespace std;      #define rng(x) x.begin(), x.end()   #define pb push_back   #define ff first   #define ss second      typedef double db;   typedef long long ll;   typedef pair<int, int> pi;   typedef pair<ll, ll> pl;   typedef vector<int> vi;   typedef vector<ll> vl;   typedef vector<vi> vvi;   typedef vector<vl> vvl;   typedef vector<bool> vb;   typedef unsigned long long int lld;      /*-----------------------------Code begins----------------------------------*/   ll mod = 1e9 + 7;   const ll INF = 1e9;      ll inv(ll v)   {    if (v<=1)     return v;    return inv(mod%v)*(mod-mod/v)%mod;   }      void solve(){       int n; cin>>n;       vvl dist(n,vl(n,INF));       for(int i=1; i<n; i++){           int u,v; cin>>u>>v;           u--; v--;           dist[u][v]=1;           dist[v][u]=1;       }       for(int i=0; i<n; i++){           dist[i][i]=0;       }       for(int k=0; k<n; k++){           for(int i=0; i<n; i++){               for(int j=0; j<n; j++){                   dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);               }           }       }       vvl prob(207,vl(207));       for(int i=0; i<=n; i++){           for(int j=0; j<=n; j++){               if(i==0){                   prob[i][j]=0;               }               else if(j==0){                   prob[i][j]=1;               }               else{                   prob[i][j] = ((prob[i-1][j] + prob[i][j-1])%mod * inv(2) )%mod;               }           }       }          ll ans=0;       for(int a=0; a<n; a++){           for(int b=a+1; b<n; b++){               for(int root=0; root<n; root++){                   int root_a = dist[a][root];                   int root_b = dist[b][root];                   int root_lca = ( root_a + root_b - dist[a][b] )/2 ;                   int lca_a = root_a - root_lca ;                   int lca_b = root_b - root_lca ;                   ans = (ans + prob[lca_a][lca_b])%mod;               }           }       }       ans = (ans * inv(n) )%mod;       cout<<ans<<  n ;   }   int main(){     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int T = 1;     //cin >> T;     while (T--){       solve();     }     return 0;   }   