//P5728
#include<bits/stdc++.h>
#define sc scanf
#define pr printf
using namespace std;
struct student
{
	int ch,ma,en,s;
}a[1001];
bool scg(student x,student y);
int main()
{
	int n,s=0;
	sc("%d",&n);
	for(int i=1;i<=n;i++)
	{
		sc("%d%d%d",&a[i].ch,&a[i].ma,&a[i].en);
		a[i].s=a[i].ch+a[i].ma+a[i].en;
	}
	for(int i=1;i<=n;i++)
		for(int j=i+1;j<=n;j++)
			if(scg(a[i],a[j])==true)
				s++;
	pr("%d",s);
	return 0;
}
bool scg(student x,student y)
{
	if(abs(x.s-y.s)<=10)
		if(abs(x.ch-y.ch<=5)&&abs(x.ma-y.ma<=5)&&abs(x.en-y.en<=5))
			return true;
	return false;
}