import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Stack;

/*
 * @author Tanzim Ibn Patowary
 * Created  May 29, 2020 9:22:05 PM
 */
public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		for (int i = 0; i < 5; i++) {
			int x = in.nextInt();
			if (x==0) {
				System.out.println(i+1);
				break;
			}
		}
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz