import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		int[] arr = new int[5];
		for (int i = 0; i < 5; i++) {
			arr[i] = scn.nextInt();
		}
		for (int i = 0; i < 5; i++) {
			int a = arr[i];
			if (a == 0) {
				System.out.println(i + 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