#include <bits/stdc++.h>
using namespace std;
pair<string,string> d[10005];
int main(){
	int n,cnt=0;
	string s,t,tt;
	pair <string,string> p;
	set <string> b;
	set <string> c;
	cin>>n;
	for (int i=0;i<4*n;i++){
		cin>>s;
		int a=0,aa=s.size()-1;
		while (s[a]!=' '){
			t=t+s[a];
			a++;
		}
		while (s[aa]!=' '){
			tt=s[aa]+tt;
			aa--;
		}
		b.insert(t);
		c.insert(tt);
		p=make_pair(t,tt);
		d[i]=p;
	}
	for (int i=0;i<n;i++){
		t=d[i].first;
		tt=d[i].second;
		if (b.count(t)>1 and c.count(tt)>0){
			cnt++;
		}
	}
	cout<<cnt<<endl;
	return 0;
}