!/usr/bin/perl

use strict;

sub set {
        my ($var, $param) = @_;
        $var = $param;
        return $var;
}
sub add {
        my ($var, $param) = @_;
        $var = ($var + $param);
        return $var;
}
sub mul {
        my ($var, $param) = @_;
        $var = ($var * $param);
        return $var;
}

my $register = 0;
while( <STDIN> )
{
        my ($command, $param) = split " ", $_;
        print $command, "->", $param, "\n";

        if( $command eq 'set' ) {
                $register = set( $register, $param );
        } elsif( $command eq 'add' ) {
                $register = add( $register, $param );
        } elsif( $command eq 'mul' ) {
                $register = mul( $register, $param );
        } else {
                die "Unknown operator: $command\n";
        }

        print "currently: $register\n";
        print "------\n";

}