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: Accepted)

#include<stdio.h>

int main(void)
{
  int n,n_1000,n_100,n_10,count=0;

  scanf("%d",&n);

  n_1000 = n / 1000;
  n = n - 1000 * n_1000;
  n_100 = n / 100;
  n = n - 100 * n_100;
  n_10 = n / 10;
  n = n - 10 * n_10;

  if(n_1000==2)
    {
      count = 1;
    }

  if(n_100==2)
    {
      count += 1;
    }

    if(n_10==2)
    {
      count += 1;
    }

    if(n==2)
    {
      count += 1;
    }

    printf("%d",count);

  return 0;
}