user@linux-mint ~/perl_practice $ more greet_add_sub.pl 
use strict;
use warnings;

sub greet_add {
	my $sum = 0;
	my @seen;
	foreach my $num (@_) {
		$sum += $num;
		print "Hi $num, you are the first one!!\n" if !@seen;
		print "Hi $num, Please join (@seen). " if @seen;
		push @seen, $num;
		print "You ", scalar @seen , " fine folks add up to: $sum\n" if scalar @seen > 1; 
		
	}
	
	print "Total is: $sum\n";
}

my @list = (1..10);
greet_add(@list);

user@linux-mint ~/perl_practice $ perl greet_add_sub.pl 
Hi 1, you are the first one!!
Hi 2, Please join (1). You 2 fine folks add up to: 3
Hi 3, Please join (1 2). You 3 fine folks add up to: 6
Hi 4, Please join (1 2 3). You 4 fine folks add up to: 10
Hi 5, Please join (1 2 3 4). You 5 fine folks add up to: 15
Hi 6, Please join (1 2 3 4 5). You 6 fine folks add up to: 21
Hi 7, Please join (1 2 3 4 5 6). You 7 fine folks add up to: 28
Hi 8, Please join (1 2 3 4 5 6 7). You 8 fine folks add up to: 36
Hi 9, Please join (1 2 3 4 5 6 7 8). You 9 fine folks add up to: 45
Hi 10, Please join (1 2 3 4 5 6 7 8 9). You 10 fine folks add up to: 55
Total is: 55
user@linux-mint ~/perl_practice $