import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	} main {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.nextLine(); s sc.nextLine() sc.nextLine sc System.out.println(s.indexOf("0") / 2 + 1) System.out.println System.out System System.out s.indexOf("0") / 2 + 1 s.indexOf("0") / 2 s.indexOf("0") s.indexOf s "0" 2 1 String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		System.out.println(s.indexOf("0") / 2 + 1);
	}
}