#include<iostream>

int count,team=0;

struct students{int Chinese,English,Math,All;};

bool Test(int A,int B,int X)
{
	if(A==B)
		return 1;
	else if(A>B && A-B<=X)
		return 1;
	else if(A<B && B-A<=X)
		return 1;
	else
		return 0;
}

int main()
{
	scanf("%d",&count);
	
	students student[count];
	
	for(int i=0;i<count;i++)
	{
		scanf("%d%d%d",&student[i].Chinese,&student[i].English,&student[i].Math);
		student[i].All=student[i].Chinese+student[i].English+student[i].Math;
	}
	
	for(int i=0;i<count;i++)
		for(int j=0;j<count;j++)
		{
			if(i==j)
				continue;
			else if(Test(student[i].Chinese,student[j].Chinese,5) &&
				    Test(student[i].English,student[j].English,5) &&
				    Test(student[i].Math,student[j].Math,5) &&
				    Test(student[i].All,student[j].All,5))
				team++;
		}
	
	printf("%d",team/2);
	
	return 0;
}