# Learn How to Work with Numbers and Strings by Implementing the Luhn Algorithm - Step 34

### Tell us what’s happening:

I already changed the value of the original digit from ‘4111-1111-4555-1142’ to ‘4111-1111-4555-1143’ and it still marks me an error

``````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 = '4111-1111-4555-1143'
card_translation = str.maketrans({'-': '', ' ': ''})
translated_card_number = card_number.translate(card_translation)

# User Editable Region

if verify_card_number(translated_card_number):
print('VALID!')
else:
print('INVALID!')

main()
``````

User Agent is: `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36`
This might be because you have a single space before `def main():`.