import java.util.Scanner;

public class hogeeee {

	public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        int i = s.length()-"1000000007".length();;
        if(i<0) {
        	System.out.println(i*-1);
        }else {
        	System.out.println(i);
        }
	}

}