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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main(){
	int N, count = 0;
	printf("数を入力してください。\n");
	scanf("%d", &N);
	
	if(N % 10 == 2) count++;
	if((N - N % 10) % 100 == 20) count++;
	if((N - N % 100) % 1000 == 200) count++;
	if((N - N % 1000) == 2000) count++;
	
	printf("2の個数は%dです\n", count);
	return 0;
}