my @x = @_;
my $y = 0;
my $i = 0;
until ($i > $#x) {
 $y = $y + $x[$i];
 $i = $i + 1;
}
$x[0] = $x[0] / $y;
$i = 1;
until ($i > $#x) {
 $x[$i] = $x[$i - 1] + $x[$i] / $y;
 $i = $i + 1;
}

$y = rand();

# This bit constitutes the "function"

$i = 0;
until ($y < $x[$i]) {
  $i = $i + 1;
}
return $i;