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".

Examples

Input

15


Output

6


Input

100000


Output

10
score = 9999999

n = int(raw_input())

sum_a = 0
while True:
    quo  = n %10
    sum_a += quo
    n = int(n/10)
    if n  == 0:
        break

if sum_a == 1:
    sum_a  =10

print sum_a

