for my $amount( qw/-1 0 1 10 100 511 512 513 999 1000 1023 1024 1025
    10000    
    100000    
    1000000    
    10000000    
    100000000    
    1000000000    
    10000000000    
    100000000000    
    1000000000000    
    10000000000000    
    100000000000000    
    1000000000000000/ )      
{
    print "$amount -> ", amount($amount), "\n";
}