use strict;
open(STDERR, ">>stderr.log" ) or die "cannot redirect stderr output in log file : $!\n";

my $file = $ARGV[0];
open my $FILE, q{<}, $file or die "cannot open the file";

my @acronyms_captured;
my %seen;

while(<FILE>){
	$_ =~ s/\s+$//;
	my @Elements  = split /\s/;
	print STDOUT "@Elements\n";
	foreach my $el (@Elements) {
		if ($el =~ /[A-Z]+/){
			if ($seen{$el} == 0){
				push @acronyms_captured, $el;
				$seen{$el} ++ ;
			}
		}
	}	
}

foreach my $acronym(@acronyms_captured){
	print STDOUT "$acronym\n";
}