#!/usr/bin/perl
use strict;
use warnings;

my $inputData = <<IN;
1
2
3
4
5
6
7
8
9
10
IN

open my $fIn, '<', \$inputData;
chomp (my @lines = <$fIn>);

printf "Average: %.2f\n", average(@lines);
printf "Largest: %d\n", largest(@lines);


sub average {
    my $sum  = 0;
    $sum += $_ for @_;
    return $sum / @_;
}


sub largest {
    my $max = shift @_;
    
    for my $value (@lines) {
        $max = $value if $value > $max;
    }
    
    return $max;
}