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F. Ace It!
time limit per test
2 seconds
memory limit per test
64 megabytes
input
standard input
output
standard output
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.

Examples
Input
A221033
Output
21
Input
A223635
Output
22
Input
A232726
Output
23