Just need to make a flowchart for Luhn's Algorithm

Luhn's Algorithm for 16 digit credit card. If the card is 16 digits in length. You will sum all the digits in the odd location. The digits in the even location must be doubled and then if the value is greater than 9 then you must sum the individual digits. Example: If you double a digit of 4 , then the new value is 8 . It is not >9, so 8 is added to the sum. If you double 6 , the new value is 12 and you would add 3(1+2) to the sum. If the sum of all the digits is divisible by 10 evenly, it is a valid number. Remember to convert from character value to integer value. Sum of Digits 70 Valid Card Number TRUE The blue columns represent a digit being doubled