Ace It!

Description:

Input:

The only line of the input is a string of 7 characters. The first character is letter A, followed by 6 digits. The input is guaranteed to be valid (for certain definition of "valid").

Output:

Output a single integer.

Sample Input:

A221033

Sample Output:

21

Sample Input:

A223635

Sample Output:

22

Sample Input:

A232726

Sample Output:

23