#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
inline int read(){
    register int x=0,f=1;register char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=0;ch=getchar();}
    while(isdigit(ch)){x=x*10+(ch^'0');ch=getchar();}
    return f?x:-x;
}

int n,P=1000000007,dis[205],ans,f[205][205];
int power(int b,int n){int ans=1;for(;n;n>>=1,b=1ll*b*b%P)if(n&1)ans=1ll*ans*b%P;return ans;}
void inc(int &a,int b){a=a+b>=P?a+b-P:a+b;}
vector<int> E[205];

vector<int> dfs(int nw,int fa){
    vector<int> a;
    a.push_back(nw);
    dis[nw]=dis[fa]+1;
    for(int i=0;i<(int)E[nw].size();++i)
	if(E[nw][i]!=fa){
	    vector<int> b=dfs(E[nw][i],nw);
	    for(int u:a)
		for(int v:b){
		    int x=u,y=v;
		    if(x>y)swap(x,y);
		    inc(ans,f[dis[x]-dis[nw]][dis[y]-dis[nw]]);
		}
	    for(int u:b)a.push_back(u);
    }
    return a;
}

int main(){
    //freopen("in.in","r",stdin);
    n=read();
    for(int i=1;i<n;++i){
	int u=read(),v=read();
	E[u].push_back(v),E[v].push_back(u);
    }
    for(int i=1;i<=n;++i)f[i][0]=1;
    int m2=power(2,P-2);
    for(int i=1;i<=n;++i)
	for(int j=1;j<=n;++j)
	    f[i][j]=1ll*(f[i-1][j]+f[i][j-1])*m2%P;
    for(int rt=1;rt<=n;++rt){
	memset(dis,0,sizeof dis);
	dfs(rt,0);
    }
    ans=1ll*ans*power(n,P-2)%P;
    printf("%d\n",ans);
    return 0;
}
