#include<bits/stdc++.h>
using namespace std;
map<string,int> tou,wei;
string s1[10005],s2[10005],s3;
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	int n,ans=0,cnt=0;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>s1[i]>>s3>>s3>>s2[i];
		tou[s1[i]]++;
		wei[s2[i]]++;
	} 
	for(int i=1;i<=n;i++){
		if(wei[s1[i]]>=1 && tou[s2[i]]>=2){
			int k=tou[s2[i]];
			ans+=(k*(k-1))/2;
			cnt++;
		}
	}
	if(cnt>=2)cout<<ans/2;
	else cout<<0;
	
	return 0;
}