my %Uniq;
while( my $Ip = NextIp() ){
   $Uniq{$Ip}++
}

my @TopDown = sort { $Fun{$b} <=> $Fun{$a} } keys %Uniq;
my @TopTen = @TopDown[0..9];

# @TopTen =  ( sort { $Fun{$b} <=> $Fun{$a} } keys %Uniq )[ 0 .. 9];