# Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 33

They are asking me to modify the ‘verified_card_number’ call in main function such that if it returns True the output should be ‘VALID!’ if it returns False the output should be ‘INVALID!’
The instruction is to include the if statement on verify_card_number within the main(), but it is already there.

``````def verify_card_number(card_number):
sum_of_odd_digits = 0
card_number_reversed = card_number[::-1]
odd_digits = card_number_reversed[::2]

for digit in odd_digits:
sum_of_odd_digits += int(digit)

sum_of_even_digits = 0
even_digits = card_number_reversed[1::2]
for digit in even_digits:
number = int(digit) * 2
if number >= 10:
number = (number // 10) + (number % 10)
sum_of_even_digits += number
total = sum_of_odd_digits + sum_of_even_digits
print(total)

# User Editable Region

def main():
card_number = '4111-1111-4555-1142'
card_translation = str.maketrans({'-': '', ' ': ''})
translated_card_number = card_number.translate(card_translation)

verify_card_number(translated_card_number)
if verify_card_number(translated_card_number):
print("VALID!")
elif:
print("INVALID!")

# User Editable Region

main()
``````

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36`

### Challenge Information:

Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 33

Hi @kaustubhkasar2014,
Welcome to fCC community. and geat work.
For conditional statements:
else is used for the last option, once all other other options have been exausted. if only two option it will be opening argument and else.
elif will be used if more than two options.

So adjust the `elif` and it go through.

happy coding.

ELIF would need a condition to check `Else if <condition>:`

As @OpeRichards mentioned `else` will execute in any other case.