map{push@L,@C+0;push@C,lc=~/./g}<>;sub p{pop@n}sub w{push@n,@_}while($n<@C){$_=
$C[$n++];if(/h/){$_=p;w$n[-1-abs];$_>0&&splice@n,-2-$_,1}if(/n/){w 0;/-/||w$_+7
*p while($_=index"htaoinse",$C[$n++])<7}$0=p,$_=p,w int$_/$0,$_%$0if/e/;if(/t/)
{$_=p;$_?$n=$L[$_-1]:last if p}/a/?w 1+grep$n>$_,@L:/o/?print chr p:/s/?w-(p)+p
:/i/&&w($_=getc)?ord:-1}