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 Julia (0.5.0) (judge verdict: Wrong Answer)

if isfile("mystdin.txt");mystdin=open("mystdin.txt","r");redirect_stdin(mystdin);end
pI(x)=parse(Int,x)
pM(x::Array{SubString{String},1})=map(pI,x)
function main()
  n=chomp(readline())
  l=length(n)
  println(n=="9"^l ? 9*l : pI(n[1])+9*l-10)
end
main()
if isdefined(Base, :mystdin);close(mystdin);end