($x,$y,$h)=glob<>;
($x,$y)=sort{$a-$b}$x,$y;
$h/=1e3;
for$i(0..19){
	for$j(0..19){
		if(
			($i==0||$x/2**($i-1)>$h*2**($i-1))&&
			($j==0||$y/2**($j-1)>$h*2**($i+$j-1))
		){
			$%+=$-=$i+$j-$%
		}
	}
}
print$%