Removing the duplicates of elements

""" This is a program that removes the duplicates of elements in a given list of
numbers supplied by the user. Please note that the number of the elements supplied
should be greater than 15, otherwise, you dont get to proceed """

type_numbers = input("Enter your list of numbers and use a comma and whitespace\
as a separator between two numbers: ")
list_of_numbers = type_numbers.split(", ") # The splits the numbers to a list

def remove_duplicates(numbers):
    mylist = list(dict.fromkeys(numbers))

    if len(numbers) <= 15: # Checking if the numbers are upto 15
        print("Error!: The number of the elements is not upto 15, it is", len(numbers))
    else:
        print("The length of the original list is: ", len(list_of_numbers))
        print("The length of the final list is: ", len(mylist))
        mylist.sort()
        print("my unique and sorted list is", mylist)

remove_duplicates(list_of_numbers)


# Enter your list of numbers and use a comma and whitespaceas a separator between two numbers: 1, 2, 3,
# 4, 3, 2
# Error!: The number of the elements is not upto 15,
# it is 6

# Enter your list of numbers and use a comma and whitespaceas a separator between two numbers: 1, 2, 4,
# 5, 5, 4, 3, 2, 4, 4, 5, 6, 3, 2, 5, 4, 3, 3, 2
# The length of the original list is:  19
# The length of the final list is:  6
# my unique list is ['1', '2', '3', '4', '5', '6']