import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		ArrayList<Integer> al = new ArrayList<>();
		for(int p =0; p<5; p++) {
			int num = sc.nextInt();
			al.add(num);
		}
		for(int p=0; p<al.size(); p++) {
			if(al.get(p)==0) {
				System.out.println(p + 1);
			}
		}
	}
}

/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