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: Runtime Error)

package atcoder_problem;

import java.util.Scanner;

public class Main {

	public static int getTwoNumbers(String number) {
		
		int index = 0;
		
		String value = String.valueOf(number);
		
		char[] chars = value.toCharArray();
		
		for(int i=0; i<chars.length; i++) {
			if(chars[i]=='2') {
				index++;
			}
		}
		
		return index;
	}
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String value = sc.next();
		
		int twoNumbers = getTwoNumbers(value);
		
		System.out.println(twoNumbers);
	}
}