import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int g = n % 10;
		int s = n / 10 % 10;
		int b = n / 100 % 10;
		int q = n / 1000;
		if(q > 0){
			System.out.println(4);
		}if(q == 0 && b > 0){
			System.out.println(3);
		}if(q == 0 && b == 0 && s > 0){
			System.out.println(2);
		}if(q == 0 && b == 0 && s == 0 && g > 0){
			System.out.println(1);
		}if(n == 0){
			System.out.println(0);
		}
		sc.close();
	}

}
/**************************************************************
	Problem: 1710
	User: admin
	Language: Java
	Result: Accepted
	Time:876 ms
	Memory:39888 kb
****************************************************************/