import java.util.Scanner;
class Main{
  public static void main(String[] args){
	  Scanner in =new Scanner(System.in);
int n=in.nextInt();
int a[]=new int[n];
int b[]=new int[n];
int c[]=new int[n];
int amount=0;
int m=n;

for(int i=0;i<n;i++)
{
	a[i]=in.nextInt();
	b[i]=in.nextInt();
	c[i]=in.nextInt();
}

 for(int i=0;i<n;i++)
 {   
	 m=n;
for(int k=0;k<m;k++)
{//这是每科差的
 if(k==i)
 {
 k++;
 }
 if(i==n-1)
{
 m--;
 }
 int q=a[i]-a[k];
 int x=b[i]-b[k];
 int v=c[i]-c[k];
		 v=Math.abs(v);		 x=Math.abs(x); q=Math.abs(q);
	
int h=a[i]+b[i]+c[i]-a[k]-b[k]-c[k];
		 h=Math.abs(h); 
  if(v<=5 && x<=5 && q<=5 && h<=10)
  {
 amount++;
  }
	  }
}
  amount=amount/2;
   System.out.print(amount);
  
  
  }
}