def binc(n, k):
	"""binc(n, k): Computes n choose k."""
	if (k > n): return 0
	if (k < 0): return 0
	if (k > int(n/2)):
		k = n - k

	rv = 1
	for j in range(0, k):
		rv *= n - j
		rv /= j + 1
	return int(rv)