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: Wrong Answer)

// 12_22.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <string>
using namespace std;

string s;
int c = 0;

int main()
{
	cin >> s;
	for (int i = 0; i < 4; i++) {
		if (s[i] == 2) {
			c++;
		}
	}

	cout << c << endl;
	return 0;
}

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// Debug program: F5 or Debug > Start Debugging menu

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