import math


def NChooseK(N, K):
	"""
	Calculate (N choose K)

	:param N: int, the size of the overall set
	:param K: int, size of the combinations chosen from set
	:return: combos, int, number of combinations possible
	"""
	
	numer = math.factorial(N)
	denom = math.factorial(K) * math.factorial(N - K)
	
	combos = numer / denom
	return int(combos)