Score : 200 points
Takahashi has two positive integers A and B.
It is known that A plus B equals N. Find the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B" (in base 10).
Input is given from Standard Input in the following format:
N
Print the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B".
15
6
When A=2 and B=13, the sums of their digits are 2 and 4, which minimizes the value in question.
100000
10