def compute_bigram(input, unigram_count, bigram_count):
	"""
	compute_bigram - function to compute bigram probability
	Inputs:
		input : tuple
			bigram
		unigram_count : defaultdict(int)
			Occurence hashmap of single words/tokens
		bigram_count : defaultdict(int)
			Occurence hasmap of bi-words/tokens
	Outputs:
		output : float
			Bigram probability
	"""
	return bigram_count[input] / unigram_count[input[0]]