#include<cstdio>

#include<algorithm>

#define MN 300001

#define ui long long

using namespace std;

ui read_p,read_ca;

inline ui read(){

    read_p=;read_ca=getchar();

    while(read_ca<''||read_ca>'') read_ca=getchar();

    while(read_ca>=''&&read_ca<='') read_p=read_p*+read_ca-,read_ca=getchar();

    return read_p;

}

ui n,N,m,l[MN],num=,fa[MN],s[MN],d[MN],_s[MN],S[MN],GS[MN],_S[MN],si[MN],MMH=,_MMH=,x,y;

struct na{ui y,ne;}b[MN<<];

inline void in(ui x,ui y){b[++num].y=y;b[num].ne=l[x];l[x]=num;}

const ui MOD=1e9+;

inline ui _M(ui x){while(x>=MOD)x-=MOD;while(x<)x+=MOD;return x;}

inline void M(ui &x){while(x>=MOD)x-=MOD;while(x<)x+=MOD;}

void dfs(ui x){

    si[x]=;

    ui i,k=,al=;

    for (i=l[x];i;i=b[i].ne) if (!si[b[i].y]) fa[b[i].y]=x,dfs(b[i].y),al=(1LL*si[x]*si[b[i].y]+al)%MOD,si[x]+=si[b[i].y],M(s[x]+=s[b[i].y]),M(k+=d[b[i].y]);

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x])

    M(MMH+=1LL*d[b[i].y]*(al-1LL*si[b[i].y]*(si[x]-si[b[i].y])%MOD)%MOD+1LL*_s[b[i].y]*(si[x]-si[b[i].y])%MOD-MOD),M(GS[x]+=1LL*s[b[i].y]*(si[x]-si[b[i].y])%MOD+GS[b[i].y]-MOD);

    s[x]=(1LL*al*si[x]+s[x])%MOD;

    M(S[x]=(1LL*(si[x]-)*si[x]>>)%MOD*si[x]%MOD-s[x]);

    d[x]=(1LL*al*(al-)>>)%MOD;

    _s[x]=k;

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x])

    d[x]=(1LL*(si[x]-si[b[i].y])*s[b[i].y]+d[b[i].y]+d[x])%MOD,_s[x]=(1LL*(k-d[b[i].y])*si[b[i].y]+_s[x]+_s[b[i].y])%MOD

    ,M(_S[x]+=(1LL*GS[b[i].y]*(si[x]-si[b[i].y])+(-1LL*si[b[i].y]*(si[x]-si[b[i].y])%MOD+al)*s[b[i].y]+_S[b[i].y])%MOD);

}

void DFS(ui x,ui v,ui _v){

    ui i,S=,AL=,k=,_k=,P=,al=,o;

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x])

    M(al+=1LL*(si[x]-si[b[i].y])*si[b[i].y]%MOD),M(k+=s[b[i].y]),M(_k+=1LL*s[b[i].y]*(n-si[b[i].y])%MOD),

    M(P+=d[b[i].y]),M(AL+=(1LL*(si[b[i].y]+)*(n-si[b[i].y])-)%MOD*si[b[i].y]%MOD);

    al=1LL*(al+si[x]-)*((MOD+)/)%MOD;

    M(MMH+=1LL*v*al%MOD);

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x]) o=S=_M((1LL*(si[x]-si[b[i].y])*(n-si[x])-1LL*(si[x]-si[b[i].y])*si[b[i].y]+al)%MOD),o=1LL*o*(n-si[b[i].y])%MOD,S=(1LL*S*(S-)>>)%MOD,

    M(S+=P-d[b[i].y]),DFS(b[i].y,_M(_M(v+_k-1LL*s[b[i].y]*(n-si[b[i].y])%MOD-1LL*(k-s[b[i].y])*si[b[i].y]%MOD)+1LL*(si[x]-si[b[i].y])*_v%MOD-MOD+S),_M(_v+k-MOD-s[b[i].y]+o));

}

void _DFS(ui x){

    ui i,k=,al=;

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x]) _DFS(b[i].y),M(al+=1LL*(si[x]-si[b[i].y])*si[b[i].y]%MOD);

    al=1LL*(al+si[x]-)*((MOD+)/)%MOD;

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x]) M(_MMH+=((1LL*(si[x]-si[b[i].y])*(n-si[x])-1LL*(si[x]-si[b[i].y])*si[b[i].y]+al)%MOD*(si[x]-si[b[i].y])%MOD+k)*s[b[i].y]%MOD),M(k+=s[b[i].y]);

    for (i=l[x];i;i=b[i].ne) if (b[i].y!=fa[x]) M(_MMH+=1LL*GS[b[i].y]*(n-si[b[i].y])%MOD*(si[x]-si[b[i].y])%MOD),M(_MMH+=1LL*_S[b[i].y]*(si[x]-si[b[i].y])%MOD);

}

int main(){

    register ui i;

    n=read();

    for (i=;i<n;i++) x=read(),y=read(),in(x,y),in(y,x);

    N=(1LL*n*(n-)>>)%MOD;m=1LL*N*(N-)%MOD*(N-)%MOD*((MOD+)/)%MOD;

    dfs();

    DFS(,,);

    _DFS();

    M(m-=MMH+_MMH);

    printf("%lld\n",m);

}