while (<DATA>) {
	chomp;
	my @letters = m/(\w)/g;
	while (@letters) {
		my $x = shift @letters;
		my $y = shift @letters;
		
		print "($x, $y) ";
	}
	print "\n";
}

__DATA__
T G T T T G T C A A
C G G C T C T G G C