use strict;
use warnings;

while (my $line = <DATA>) {
	$line =~ s/,//g;
	my @n = split(/\s+/, $line);
	my $sum = 0;
	for (@n) {$sum += $_};
	print $sum / ($#n + 1), "\n";
}

__DATA__
2,800  2,900 3,000  3,000  2,988 
5,000  5,495 4,999  4,995  4,900     

##</code><code>##

2937.6
5077.8