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
def main():
    N = input()
    if N%10 != 0:
        print(digitSum(N))
    else:
        print(digitSum(N)*10)

def digitSum(n):
    s = str(n)
    array = list(map(int, list(s)))
    return sum(array)

if __name__ == '__main__':
    main()
