#!perl
use strict;
use Math::BigInt;
 
sub HeX {
    my $n = shift;
    $n = '0' x (4 - (length($n) % 4)) . $n;
    my $m = Math::BigInt->new(0);
    while (my $o = substr($n, 0, 4, '')){
        $m = $m * 65536 + hex $o;
    } $m;
}