RANDOM num
(RANDOM start end)

	with one input, outputs a random nonnegative integer less than its
	input, which must be a positive integer.

	With two inputs, RANDOM outputs a random integer greater than or
	equal to the first input, and less than or equal to the second
	input.  Both inputs must be integers, and the first must be less
	than the second.  (RANDOM 0 9) is equivalent to RANDOM 10;
	(RANDOM 3 8) is equivalent to (RANDOM 6)+3.