#!usr/bin/perl
use strict;
use warnings;

my %buckets;

my @array2 = (["A","B"],["C","D"],["A","C"],["E","F"],["F","G"]);
my $count = 0;
foreach(@array2){
	my $req1 = $array2[$count][0];
	my $req2 = $array2[$count][1];
	my $j = 0;
	foreach my $key (keys %buckets){
		if($key =~ /$req1/i){
			$buckets{$key} .= $req2;
			$j++;
			last;
		}
		elsif($key =~ /$req2/i){
			$buckets{$key} .= $req1;
			$j++;
			last;
			}
		elsif($buckets{$key} =~ /$req1/i){
			$buckets{$key} .= $req2;
			$j++;
			last;
			}
		elsif($buckets{$key} =~ /$req2/i){
			$buckets{$key} .= $req1;
			$j++;
			last;
			}		
		}
		if($j == 0){$buckets{$req1} = $req2;}
	$count++;
	}
	
	foreach(keys %buckets){print $_,$buckets{$_},"\n";}