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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main() {
	
	int N = 0;
	scanf("%d",&N);
	
	int save = 0, count = 0;
	for( int i = 0; i < 4; i++ ){
		save = N % 10;
		if( save == 2 ){
			count++;
		}
		N = N / 10;
	}
	
	printf("%d",count);
	
	return 0;
}