#include <iostream>
#include <cmath>
#include <vector>
using namespace std;

int num;
int flag;

struct grade
{
	int chinese;
	int math;
	int english;
	int score;
}stu;
vector <grade> p;

int main() {

	cin >> num;

	for (int i = 0; i < num; i++)
	{
		cin >> stu.chinese >> stu.math >> stu.english;
		stu.score = stu.chinese + stu.english + stu.math;
		p.push_back(stu);
		
	}
	for (int i = 0; i < p.size(); i++)
	{
		for (int j = i+1; j < p.size(); j++) {
			if (abs(p[i].chinese-p[j].chinese)<=5&&abs(p[i].math-p[j].math)<=5&&abs(p[i].english-p[j].english)<=5&&(p[i].score-p[j].score)<=10)
			{
				flag += 1;
			}
		}
	}

	cout << flag;
	return 0;
}