#!/usr/bin/perl
use warnings;
use strict;
my $total;
for my $i (1..6) {
for my $j (1..6) {
for my $k (1..6) {
for my $l (1..6) {
    # get the sum for this dice-roll
    my @roll = (sort ($i, $j, $k, $l))[1..3];
    $total += eval join '+', @roll ;
}}}}
print $total/6**4