#include<stdio.h>
#include <stdlib.h>
int main(void)
{
	int N;
	int i, j, temp;
	int sum1;
	int grade[1000][3];
	int sum[1000]; 
	temp = 0;
	scanf("%d",&N);
	for(i=0;i<N;i++)
	{
	scanf("%d %d %d",&grade[i][0],&grade[i][1],&grade[i][2]);
	sum[i] = grade[i][0]+grade[i][1]+grade[i][2];
	}
	for(i=0;i<N;i++)
	{
		for(j=i+1;j<N;j++)
		{
			if(abs(grade[i][0]-grade[j][0])<=5&&abs(grade[i][1]-grade[j][1]<=5)&&abs(grade[i][0]-grade[j][0])<=5&&abs(sum[i]-sum[j])<=5)
			temp++;
		}
	}
	printf("%d",temp);
	return 0;
}