import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// contest 170
		Scanner sc = new Scanner(System.in);
		// List<Integer> l = Arrays.asList(sc.nextInt().split(" "));
		int x = sc.nextInt();
		int y = sc.nextInt();
		int z = sc.nextInt();
		int w = sc.nextInt();
		int s = sc.nextInt();
		if (x == 0) {
			System.out.print(1);
		}
		if (y == 0) {
			System.out.print(2);
		}
		if (z == 0) {
			System.out.print(3);
		}
		if (w == 0) {
			System.out.print(4);
		}
		if (s == 0) {
			System.out.print(5);
		}
	}
}

/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