--- beginning of data ---
1-2,3-4,2-5
2-1,2-5
3-5,1-9,2-2,4-8
 --- end of data ---

use warnings;
use strict;

while (<>) {
	chomp;
	my @dashpairs = split(/,/);
	foreach my $dashpair (@dashpairs) {
		my ($num1, $num2) = split(/-/,$dashpair);
		print "$num1 - $num2\n";
	}
}