#include<iostream>
#include<cmath>
using namespace std;
struct student {
	int a;
	int b;
	int c;
	int sum;
};
int main() {
	int n;
	cin >> n;
	struct student s[1001];
	int count = 0;
	for (int i = 1; i <= n; i++) {
		cin >> s[i].a >> s[i].b >> s[i].c;
	}
	for (int i = 1; i <= n ; i++) {
		for (int j = i + 1; j <= n; j++) {
			if (abs(s[i].a - s[j].a) <= 5 && abs(s[i].b - s[j].b) <= 5 && abs(s[i].c - s[j].c) <= 5) {
				s[i].sum = s[i].a + s[i].b + s[i].c;
				s[j].sum = s[j].a + s[j].b + s[j].c;
				if (abs(s[i].sum - s[j].sum) <= 10) {
					count++;
				}
			}
		}
	}
	cout << count << endl;
	return 0;
}