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 Pascal (FPC 2.6.2) (judge verdict: Accepted)


uses SysUtils;
var i,y,i1,x,a,b:Longint;
    ans,n:Longint;

begin
 
 readln(n);
 ans:=9999999;
 for i:=1 to n-1 do begin
      a:=trunc(i); b:=trunc(n)-a;
      //writeln('a=',a,'b=',b);
      x:=0;
      for i1:=1 to length(inttostr(a)) do inc(x,strtoint(copy(inttostr(a),i1,1)));
      //writeln('a ',a,' kakui wa=',x);
      y:=0;
      for i1:=1 to length(inttostr(b)) do inc(y,strtoint(copy(inttostr(b),i1,1)));
      //writeln('b ',b,' kakui wa=',y);
      if ans>x+y then ans:=x+y;
      end;
writeln(trunc(ans));
end.