import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		List<Integer> nums = new ArrayList<Integer>();
		for(int i = 0; i < 5; i++) {
			nums.add(scanner.nextInt());
			if(nums.get(i) == 0) {
				System.out.println(i + 1);
				break;
			}
		}
		scanner.close();
	}
}
/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