my $port = "3030";
if ($port eq "3010"){
	my $port2 = "3100";
	print $port2;
}
elsif ($port eq "3020"){
	my $port2 = "3200";
	print $port2;
}
elsif ($port eq "3030"){
	my $port2 = "3300";
	print $port2;
}
elsif ($port eq "3040"){
	my $port2 = "3400";
	print $port2;
}
elsif ($port eq "3050"){
	my $port2 = "3500";
	print $port2;
}
else{
	print "no port\n";
}

my %ports = (
  3010 => 3100,
  3020 => 3200,
  3030 => 3300,
  3040 => 3400,
  3050 => 3500,
);

my $port = "3030";
unless (exists $ports{$port}) {
    print "no port\n";
}
else {
  my $port2 = $ports{$port};
  print $port2;
}