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 main
	implicit none
    integer::a,ans,i
    read(*,*) a
    ans=0
    do i=1,4
    	if(mod(a,10)==2)then
        	ans=ans+1
            
        end if
        a=a/10
    end do
    write(*,*) ans
    stop
end program main