using namespace std;
struct stu {
	int chinese;
	int english;
	int math;
};
int main()
{
	stu student[1000];
	int n;
	int a=0;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>student[i].english;
		cin>>student[i].chinese;
		cin>>student[i].math; 
	} 
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			if(abs(student[i].chinese-student[j].chinese)<=5&&abs(student[i].english-student[j].english)<=5&&abs(student[i].math-student[j].math)<=5&&abs(student[i].chinese+student[i].english+student[i].math-student[j].chinese-student[j].english-student[j].math<=10)){
				a++;
			}
		}
	}
	cout<<a;
	return 0;
}```