import java.util.Scanner;
// A - Multiplication 1
class Main{
	public static void main(String[] args){

		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		int C = sc.nextInt();
		int D = sc.nextInt();
		int E = sc.nextInt();

		int ans;

		if (A == 0) {
			System.out.println("1");
		}
		if (B == 0) {
			System.out.println("2");
		}
		if (C == 0) {
			System.out.println("3");
		}
		if (D == 0) {
			System.out.println("4");
		}
		if (E == 0) {
			System.out.println("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