Problem:
Score : 300 points

Problem Statement

Find the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Constraints

1\leq N \leq 10^{16}

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Sample Input 1

100

Sample Output 1

18

For example, the sum of the digits in 99 is 18, which turns out to be the maximum value.

Sample Input 2

9995

Sample Output 2

35

For example, the sum of the digits in 9989 is 35, which turns out to be the maximum value.

Sample Input 3

3141592653589793

Sample Output 3

137

Solution in Pascal (FPC 2.6.2) (judge verdict: Wrong Answer)

var
 max,i,j,n,m,a,xx:longint;
 s:ansistring;
begin
 read(s); 
 m:=0; max:=-1;
 val(s,a,xx);
 for j:=1 to a do
  begin
   str(j,s);
   n:=length(s);
   for i:=1 to n do
    m:=m+ord(s[i])-48;
   if m>max then max:=m;
   m:=0;
  end;
 write(max);
end.