#include <bits/stdc++.h>
using namespace std;
#define OPENIOBUF

namespace FastIO
{

class FastIOBase
{
 protected:
#ifdef OPENIOBUF
	static const int BUFSIZE=1<<16;
	char buf[BUFSIZE+1];
	int buf_p=0;
#endif
	FILE *target;
	FastIOBase(FILE *f): target(f){}
	~FastIOBase()=default;
 public:
#ifdef OPENIOBUF
	virtual void flush()=0;
#endif
};

class FastOutput final: public FastIOBase
{
 public:
	FastOutput(FILE *f=stdout): FastIOBase(f) {}
#ifdef OPENIOBUF
	~FastOutput() { flush(); }
	void flush() { fwrite(buf,1,buf_p,target),buf_p=0; }
#endif
	void put(char x)
	{
#ifdef OPENIOBUF
		if(buf[buf_p++]=x,buf_p==BUFSIZE) flush();
#else
		putc(x,target);
#endif
	}
	FastOutput &operator <<(char x)
	{ return put(x),*this; }
	FastOutput &operator <<(const char *s)
	{ for(;*s;put(*(s++)));return *this; }
	FastOutput &operator <<(const std::string &s)
	{ return (*this)<<s.c_str(); }
	template<typename T>
	std::enable_if_t<std::is_integral<T>::value,FastOutput&> operator <<(T x)
	{
		if(x<0) return put('-'),(*this)<<(-x);
		char stk[std::numeric_limits<T>::digits10+1],*top=stk;
		do *(top++)=x%10+'0',x/=10; while(x);
		while(top!=stk) put(*(--top));
		return *this;
	}
	template<typename ...T>
	void writesp(T &&...x)
	{ std::initializer_list<int>{((*this)<<(x),put(' '),0)...}; }
	template<typename ...T>
	void writeln(T &&...x)
	{ std::initializer_list<int>{((*this)<<(x),put('\n'),0)...}; }
	template<typename Iter>
	std::enable_if_t<std::is_base_of<
		std::forward_iterator_tag,
		typename std::iterator_traits<Iter>::iterator_category>
	::value> writesp(Iter begin,Iter end)
	{ while(begin!=end) (*this)<<*(begin++)<<' '; }
	template<typename Iter>
	std::enable_if_t<std::is_base_of<
		std::forward_iterator_tag,
		typename std::iterator_traits<Iter>::iterator_category>
	::value> writeln(Iter begin,Iter end)
	{ while(begin!=end) (*this)<<*(begin++)<<'\n'; }
}qout;

class FastInput final: public FastIOBase
{
 private:
	bool __eof;
 public:
	FastInput(FILE *f=stdin): FastIOBase(f),__eof(false)
#ifdef OPENIOBUF
	{ buf_p=BUFSIZE; }
	void flush() { buf[fread(buf,1,BUFSIZE,target)]=EOF,buf_p=0; }
	bool eof()const { return buf[buf_p]==EOF; }
#else
	{}
	bool eof()const { return feof(target); }
#endif
	char get()
	{
		if(__eof) return EOF;
#ifdef OPENIOBUF
		if(buf_p==BUFSIZE) flush();
		char ch=buf[buf_p++];
#else
		char ch=getc(target);
#endif
		return ~ch?ch:(__eof=true,EOF);
	}
	void unget(char c)
	{
		__eof=false;
#ifdef OPENIOBUF
		buf[--buf_p]=c;
#else
		ungetc(c,target);
#endif
	}
	explicit operator bool()const { return !__eof; }
	FastInput &operator >>(char &x)
	{ while(isspace(x=get()));return *this; }
	template<typename T>
	std::enable_if_t<std::is_integral<T>::value,FastInput&> operator >>(T &x)
	{
		char ch,sym=0;x=0;
		while(isspace(ch=get()));
		if(__eof) return *this;
		if(ch=='-') sym=1,ch=get();
		for(;isdigit(ch);x=(x<<1)+(x<<3)+(ch^48),ch=get());
		return unget(ch),sym?x=-x:x,*this;
	}
	FastInput &operator >>(char *s)
	{
		while(isspace(*s=get()));
		if(__eof) return *this;
		for(;!isspace(*s) && !__eof;*(++s)=get());
		return unget(*s),*s='\0',*this;
	}
	FastInput &operator >>(std::string &s)
	{
		char str_buf[(1<<8)+1]={0},*p=str_buf;
		char *const buf_end=str_buf+(1<<8);
		while(isspace(*p=get()));
		if(__eof) return *this;
		for(s.clear(),p++;;p=str_buf)
		{
			for(;p!=buf_end && !isspace(*p=get()) && !__eof;p++);
			if(p!=buf_end) break;
			s.append(str_buf);
		}
		unget(*p),*p='\0',s.append(str_buf);
		return *this;
	}
	template<typename ...T>
	void read(T &&...x)
	{ std::initializer_list<int>{((*this)>>(x),0)...}; }
	template<typename Iter>
	std::enable_if_t<std::is_base_of<
		std::forward_iterator_tag,
		typename std::iterator_traits<Iter>::iterator_category>
	::value> read(Iter begin,Iter end)
	{ while(begin!=end) (*this)>>*(begin++); }
}qin;

} // namespace FastIO
using FastIO::qin,FastIO::qout;

using LL=long long;
using LD=long double;
using UI=unsigned int;
using ULL=unsigned long long;

#ifndef DADALZY
#define FILEIO(file) freopen(file".in","r",stdin),freopen(file".out","w",stdout)
#define LOG(...) [](auto...){}(__VA_ARGS__)
#else
#define FILEIO(file) freopen("lct2.in","r",stdin)
#define LOG(...) fprintf(stderr,__VA_ARGS__)
#endif

constexpr int MAXN=5e5;

int T,n;
LL ans;
vector<int> G[MAXN+5];

int hgt[MAXN+5],siz[MAXN+5],dep[MAXN+5],son[MAXN+5],top[MAXN+5],bot[MAXN+5],anc[MAXN+5];
vector<int> _f[MAXN+5],_g1[MAXN+5],_g2[MAXN+5];
int *f[MAXN+5],*g1[MAXN+5],*g2[MAXN+5];
void dfs1(int u,int fa=0)
{
	for(auto &v: G[u])
	{
		if(v==fa) continue;
		dfs1(v,u);
		if(hgt[v]>hgt[son[u]]) son[u]=v;
	}
	hgt[u]=max(hgt[u],hgt[son[u]]+1);
}
void dfs2(int u,int tp,int fa=0)
{
	top[u]=tp;
	if(u==tp) _f[u]=vector<int>(hgt[u]+1,0);
	f[u]=_f[tp].data()+(hgt[tp]-hgt[u]);
	if(son[u]) dfs2(son[u],tp,u);
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		dfs2(v,v,u);
	}
}
void dfs3(int u,int fa=0)
{
	siz[u]=1,dep[u]=dep[fa]+1;
	for(auto &v: G[u])
	{
		if(v==fa) continue;
		dfs3(v,u);
		siz[u]+=siz[v];
		if(siz[v]>siz[son[u]]) son[u]=v;
	}
}
void dfs4(int u,int tp,int fa=0)
{
	top[u]=tp,anc[u]=fa;
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		dfs4(v,v,u);
	}
	if(son[u]) dfs4(son[u],tp,u);
	else
	{
		bot[tp]=u;
		_g1[tp]=vector<int>(siz[tp]+1,0);
		_g2[tp]=vector<int>(siz[tp]+1,0);
	}
	g1[u]=_g1[tp].data()+(dep[bot[tp]]-dep[u]);
	g2[u]=_g2[tp].data()+(dep[u]-dep[tp]);
}

vector<pair<LL,int>> qry1[MAXN+5],qry2[MAXN+5];
vector<int> tmp[MAXN+5];
LL h1[MAXN+5],h2[MAXN+5];
int all[MAXN+5];
void solve1(int u,int fa=0)
{
	if(son[u]) solve1(son[u],u);
	int mxd=0;
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		solve1(v,u);
		mxd=max(mxd,hgt[v]);
	}
	// case 3
	fill(h1,h1+mxd+1,0);
	fill(h2,h2+mxd+1,0);
	for(auto &v: G[u])
	{
		if(v==fa) continue;
		int lim=min(mxd,hgt[v]);
		for(int i=1;i<=lim;i++)
		{
			h1[i]+=f[v][i-1];
			h2[i]+=(LL)f[v][i-1]*f[v][i-1];
		}
	}
	for(auto &v: G[u])
	{
		if(v==fa) continue;
		int lim=min(mxd-1,hgt[v]);
		for(int i=1;i<=lim;i++)
		{
			LL s1=h1[i+1]-f[v][i],
			   s2=h2[i+1]-(LL)f[v][i]*f[v][i];
			ans+=(f[v][i-1]-f[v][i])*(s1*s1-s2)/2;
		}
	}
	// case 2
	qry2[u].emplace_back(f[u][1],1);
	// update
	f[u][0]=f[u][1]+1;
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		// case 1
		for(int i=1;i<=hgt[v];i++)
		{
			LL c=f[u][i]*LL(f[v][i-1]-f[v][i]);
			qry1[u].emplace_back(c,i-1);
		}
		for(int i=1;i<=hgt[v];i++)
		{
			LL c=f[v][i]*LL(f[u][i]-f[u][i+1]);
			qry1[u].emplace_back(c,i-1);
		}
		// case 2
		for(int i=1;i<=hgt[v];i++)
		{
			LL c=f[u][i+1]*LL(f[v][i-1]-f[v][i]);
			qry2[u].emplace_back(c,i+1);
		}
		for(int i=0;i<=hgt[v];i++)
		{
			LL c=f[v][i]*LL(f[u][i]-f[u][i+1]);
			qry2[u].emplace_back(c,i+1);
		}
		// update
		for(int i=1;i<=hgt[v];i++) f[u][i]+=f[v][i-1];
		f[u][0]+=f[v][0];
	}
}
void addall(int u,int d,vector<int> &res,int fa=0)
{
	res[d]++;
	for(auto &v: G[u])
		if(v!=fa) addall(v,d+1,res,u);
}
void solve2(int u,int fa=0)
{
	auto work=[&](int k) {
		int res=0;
		for(int x=u;x;x=anc[top[x]])
		{
			int y=top[x],kk=k-(dep[u]-dep[x]);
			if(kk<0) { res+=all[y]+siz[son[x]];continue; }
			if(u!=x) res+=(kk>hgt[x]-1?0:g2[x][kk])-(kk==0);
			kk+=dep[bot[y]]-dep[x];
			res+=(kk>=_g1[y].size()?0:_g1[y][kk]);
		}
		return res;
	};
	int tp=top[u];
	g1[u][0]=g1[u][1]+1,all[tp]++;
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		tmp[v]=vector<int>(hgt[v]+1);
		addall(v,1,tmp[v],u);
		partial_sum(tmp[v].rbegin(),tmp[v].rend(),tmp[v].rbegin());
		all[tp]+=siz[v];
		for(int i=0;i<=hgt[v];i++) g1[u][i]+=tmp[v][i];
	}
	if(son[u]) solve2(son[u],u);
	g2[u][0]=g2[u][1]+1;
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		for(int i=0;i<=hgt[v];i++) g1[u][i]-=tmp[v][i];
		all[tp]-=siz[v];
		solve2(v,u);
		for(int i=0;i<=hgt[v];i++) g1[u][i]+=tmp[v][i];
		all[tp]+=siz[v];
	}
	for(auto &v: G[u])
	{
		if(v==fa || v==son[u]) continue;
		for(int i=0;i<=hgt[v];i++) g2[u][i]+=tmp[v][i];
		for(int i=0;i<=hgt[v];i++) g1[u][i]-=tmp[v][i];
		all[tp]-=siz[v];
	}
	all[tp]--,g1[u][0]=0;
	for(auto &[c,k]: qry1[u]) ans+=c*(n-siz[u]+1-work(k+1));
	for(auto &[c,k]: qry2[u]) ans+=c*work(k);
}

int main()
{
	while(qin>>n)
	{
		for(int i=1,u,v;i<n;i++)
		{
			qin>>u>>v;
			G[u].push_back(v);
			G[v].push_back(u);
		}
		dfs1(1),dfs2(1,1);
		solve1(1);
		dfs3(1),dfs4(1,1);
		solve2(1);
		qout<<(LL(n)*(n-1)*(n-2)-2*ans)<<'\n';

		// cleaning
		ans=0;
		for(int i=1;i<=n;i++)
		{
			G[i].clear(),_f[i]=vector<int>{},_g1[i]=vector<int>{};
			qry1[i].clear(),qry2[i].clear();
			hgt[i]=siz[i]=dep[i]=0;
			son[i]=top[i]=bot[i]=anc[i]=0;
			all[i]=0;
		}
	}
	return 0;
}
/*
8
3 2
4 7
5 8
6 8
7 1
2 4
1 5

*/