use warnings;
use strict;

my %hash = (4 => '1', 5 => '5', 7 => '2', 1 => '7', 10 => '9', 3 => '0', 2 => '3', 9 => '8');

print GetSecondLargest(values %hash);

sub GetSecondLargest
{
my @largest = (shift);

while (@_)
  {
  my $new = shift;
  if ($new >= $largest [-1])
    {
    unshift @largest, $new;
    next;
    }
    
  $largest[1] = $new if ! $#largest or $new > $largest[1];
  }
  
return $#largest ? $largest[1] : undef;
}