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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
    	Scanner sc = new Scanner(System.in);
    	int N = sc.nextInt();
    	int cnt = 0;
    	for(int i=3; i>=0; i--) {
    		int answer = (int) (N/(Math.pow(10, i)));
    		N %= Math.pow(10, i);
    		if(answer == 2) {
    			cnt++;
    		}
    	}
	    System.out.println(cnt);
    }
}