#include<bits/stdc++.h>
using namespace std;
int n,yw[10000],sx[10000],yy[10000],zf[10000],x;
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>yw[i]>>sx[i]>>yy[i];
		zf[i]=yw[i]+sx[i]+yy[i];
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n-i;j++){
	        if((yw[i]-yw[i+j]<=5||yw[i]-yw[i+j]<=-5)&&(sx[i]-sx[i+j]<=5||sx[i]-sx[i+j]<=-5)&&(yy[i]-yy[i+j]<=5||yy[i]-yy[i+j]<=-5)&&(zf[i]-zf[i+j]<=10||zf[i]-zf[i+j]<=-10))
	            x++;
	    }
    }
    cout<<x;
    return 0;
}