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def kaprekar(number):
    num = str(number)
    count = 0
    for i in range(len(num) - 1):
        if(num[i] == num[i+1]):
            count += 1
    if(len(num) - count == 1):
        print("Please enter a different number with atleast 2 unqiue digits!!")
    else:
        next_num != None
        while next_num != 0:
            Ao = "".join(sorted(str(number).zfill(4)))
            Do = "".join(sorted(str(number).zfill(4),reverse=True))
            print(Ao,Do)
            next_num = int(Do) - int(Ao)
            number = next_num
            if(number == 6174):
                print(number)
                print("This is kaprekars constant")
                break

number1 = int(input("Enter a number: "))
print(kaprekar(number1))