Problem:
Score : 200 points

Problem Statement

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).

Constraints

2 ≤ N ≤ 10^5

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B".

Sample Input 1

15

Sample Output 1

6

When A=2 and B=13, the sums of their digits are 2 and 4, which minimizes the value in question.

Sample Input 2

100000

Sample Output 2

10

Solution in Python (3.4.3) (judge verdict: Accepted)

#
import sys
import math
import numpy as np




n = int(input())
min_sum=9999999
for a in range(1,n):
    aa=a
    bb=n-a
    sumab = 0
    while aa > 0:
        sumab += (aa % 10)
        aa = aa // 10
    while bb > 0:
        sumab += (bb % 10)
        bb = bb // 10
    min_sum = min(min_sum,sumab)
print(min_sum)