Problem:
Score : 100 points

Problem Statement

You are given an integer N that has exactly four digits in base ten.
How many times does 2 occur in the base-ten representation of N?

Constraints

1000 \leq N \leq 9999

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer.

Sample Input 1

1222

Sample Output 1

3

2 occurs three times in 1222. By the way, this contest is held on December 22 (JST).

Sample Input 2

3456

Sample Output 2

0

Sample Input 3

9592

Sample Output 3

1

Solution in Fortran (GNU Fortran 9.2.1) (judge verdict: Accepted)

program prob61
    implicit none
    character(4) :: s
    integer :: c, i
    read(*,*) s
    c = 0

    do i = 1, 4
        if(s(i:i) == '2')then
            c = c + 1
        end if
    end do
    write(*,*) c

    stop
contains
end program prob61