#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use PDL;


sub load {
    my ($filename) = @_;
    open my $FH, '<', $filename or die $!;
    return pdl(join "\n", map { chomp; "[$_]" } <$FH>)
}


my @matrices = map load($_), @ARGV;
my $result = $matrices[0];
$result += $_ for @matrices[ 1 .. $#matrices ];
$result /= @ARGV;
say $result;