A checksum is a type of simple error detection scheme, meant to catch incorrectly entered data such as typos. Credit cards, for example, use the Luhn algorithm to generate account numbers. Alternatively, a checksum could be a digit appended to the end of a number that needs to be later validated.
A super-simple scheme used to validate 6-digit student numbers is as follows:
- Break the number up into 6 digits.
- Add up all the digits together to get a new number.
- Repeat the process until the result is only a single digit.
- Convert the resulting digit to a capital letter, where A = 1, B = 2, etc.
Example:
- 123456
- 1 + 2 + 3 + 4 + 5 + 6 = 21
- 2 + 1 = 3
- 3 = C
The input file DATA2.txt will contain 5 lines, each being a 6-digit positive integer followed by a space and a capital letter. Numbers will not have leading zeros, and thus digits will never add up to 0.
The output file OUT2.txt will contain 5 lines, stating match or error, depending on if the number generates the same checksum letter as supplied or not.
Sample Input:
123456 C
123456 A
100000 A
111111 F
111114 I
Sample Output:
match
error
match
match
match