Given a list of numbers, write a Python program to find the number which occurs the most in the list
list1 = [1, 2, 3, 4, 4, 3, 3, 3]
def most_frequent(list1): 
	return max(set(list1), key = list1.count) 

list1 = [1, 2, 3, 4, 4, 3, 3, 3]
print("Number that occurs the most in the list is : ", most_frequent(list1))