our @VAL = ( 0 .. 9, 'a' .. 'z' ); # edit
our %VAL = map { $VAL[$_] => $_ } 0 .. $#VAL;

sub parseInt {
    my( $str, $base, $int ) = @_;
    $int ||= 0;

    $str =~ /^(.)(.*)$/ ? parseInt( $2, $base, $int * $base + $VAL{lc $1} )
                        : $int;
} # parseInt

sub toString {
    my( $int, $base ) = @_;
    
    $int > 0 ? (toString( int($int/$base), $base ) || '') . $VAL[$int % $base]
             : '0'; # edit
} # toString