/*
TASK:tri
LANG:C++
*/
#include<iostream>
using namespace std;
int main() 
{
    int i,j,br=0,k=0,n,a[25000][4],u;
    cin>>n;
    k++;
    cin>>a[k][1]>>a[k][2];
    while(a[k][1])
    {
           k++;
           cin>>a[k][1]>>a[k][2];
    }
    for(i=1;i<=k;i++)
    {
                     for(j=i+1;j<=k;j++)
                     {
                                        if(a[i][1]==a[j][1])
                                        {
                                        for(u=i+1;u<=k;u++)
                                        if((a[u][2]==a[i][2] && a[u][1]==a[j][2])||(a[u][1]==a[i][2] && a[u][2]==a[j][2]))br++;
                                        }
                                        if(a[i][1]==a[j][2])
                                        {
                                        for(u=i+1;u<=k;u++)
                                        if((a[u][2]==a[i][2] && a[u][1]==a[j][1])||(a[u][1]==a[i][2] && a[u][2]==a[j][1]))br++; 
                                        }
                     }
    }
    cout<<br<<endl;
    return 0;
}
