#include<bits/stdc++.h>
using namespace std;
int main(){
	int x,s=0;
	cin>>x;
	string a,b,c,d,a1,b1,c1,d1;
	for(int i=1;i<=x/2;i++){
		cin>>a>>b>>c>>d;
		cin>>a1>>b1>>c1>>d1;
		if(d==a1 || a==d1){
			s++;
			cout<<endl;
			cout<<a1<<' '<<d<<endl<<endl;
		}
	}
	cout<<s;
}
/*
hua xiang niao yu
yu miao tian xia
xia li ba ren
ren mian tao hua
hua qian yue xia
yu chu jing ren
ji xiang ru yi
xin xiang shi cheng
cong ming ling li
jian kang cheng zhang
*/