<>;
for(<>){
	/ /;
	if(!grep{((@{$a=$_[$'/15+$_/5][$`/15+$_%5]}[0]//-20)-$`)**2+(@$a[1]-$')**2<400}0..24){
		$_[$'/15+2][$`/15+2]=[$`,$'];
		++$z
	}
}
print$z