<>;
@a=glob<>;
map{
	$x=$a[$i++]<$_|0;
	$y=$x^1;
	$\+=push@$x,$i-1;
	pop@$y while@$y&&$a[$$y[-1]]<$_^$y;
	if(@$y){
		$j=$$y[-1];
		$a=-1;$b=@$x;
		${$$x[$c]<$j?a:b}=$c=$a+$b>>1while$a+1<$b;
		$\-=$b;
	}
}@a[1..$#a];
print