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
N = int(input())
min = 999999

A = 0
B = 0

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

for i in range(1, N/2+1):
    a = i
    b = N - i

    if min > digitSum(a) + digitSum(b):
        min = digitSum(a) + digitSum(b)   

print(min)
