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?

Input

Input is given from Standard Input in the following format:
N

Output

Print the answer.

Constraints

• $1000 \leq N \leq 9999$

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

见题面 Input 部分

见题面 Output 部分