1 /**************************************************************
 2     Problem: 3522
 3     User: Tunix
 4     Language: C++
 5     Result: Accepted
 6     Time:7168 ms
 7     Memory:1452 kb
 8 ****************************************************************/
 9  
10 //BZOJ 3522
11 #include<vector>
12 #include<cstdio>
13 #include<cstring>
14 #include<cstdlib>
15 #include<iostream>
16 #include<algorithm>
17 #define rep(i,n) for(int i=0;i<n;++i)
18 #define F(i,j,n) for(int i=j;i<=n;++i)
19 #define D(i,j,n) for(int i=j;i>=n;--i)
20 #define pb push_back
21 using namespace std;
22 inline int getint(){
23     int v=0,sign=1; char ch=getchar();
24     while(ch<‘0‘||ch>‘9‘){ if (ch==‘-‘) sign=-1; ch=getchar();}
25     while(ch>=‘0‘&&ch<=‘9‘){ v=v*10+ch-‘0‘; ch=getchar();}
26     return v*sign;
27 }
28 const int N=5010,INF=~0u>>2;
29 typedef long long LL;
30 /******************tamplate*********************/
31 int to[N*2],next[N*2],head[N],cnt;
32 void ins(int x,int y){to[++cnt]=y; next[cnt]=head[x]; head[x]=cnt;}
33 void add(int x,int y){ins(x,y); ins(y,x);}
34  
35 bool vis[N];
36 int n,f[N],g[N],tmp[N],dep[N];
37 LL ans;
38 void dfs(int x,int fa){
39     tmp[dep[x]]++;
40     for(int i=head[x];i;i=next[i]) 
41         if(to[i]!=fa){
42             dep[to[i]]=dep[x]+1;
43             dfs(to[i],x);
44         }
45 }
46  
47 int main(){
48 #ifndef ONLINE_JUDGE
49     freopen("3522.in","r",stdin);
50     freopen("3522.out","w",stdout);
51 #endif
52     n=getint();
53     int x,y;
54     F(i,2,n){
55         x=getint(); y=getint();
56         add(x,y);
57     }
58     F(x,1,n){
59         memset(g,0,sizeof g);
60         memset(f,0,sizeof f);
61         for(int i=head[x];i;i=next[i]){
62             memset(tmp,0,sizeof tmp);
63             dep[to[i]]=1;
64             dfs(to[i],x);
65             F(j,1,n){
66                 ans+=(LL)g[j]*tmp[j];
67                 g[j]+=f[j]*tmp[j];
68                 f[j]+=tmp[j];
69             }
70         }
71     }
72     printf("%lld\n",ans);
73     return 0;
74 }