while (<IN>) { 
	my $bits = unpack("b*", $_);
	@array = split(//, $bits);
	foreach $value (@array) { 
		$y++;
		$tmp = $tmp . $value;
		if ($y == 2) { 
			if ($tmp =~ /00/) { 
				$tmp = '11';
			} elsif ($tmp =~ /11/) { 
				$tmp = '00';
			} 
			print OUT $tmp;
			$y = 0;
			$tmp = '';
		} 
	} 
}