use strict;

use warnings;

my $i = 0;

my $input = "";


while ($i < 3) {

  chomp(my $num = <>);

  $input .= $num . "". $num;

  $i++;

}

print "Total input is $input\n";

my @nums = split(' ', $input);

foreach (@nums) {

  my $sum += $_;

}

print my $sum / @nums . "\n";

exit;