import java.util.*;
import java.io.*;
import java.lang.*;

public class Main {
	public static void main (String[] args) {
		int[] arr = new int[5];
		Scanner sc = new Scanner (System.in);
		for (int i = 0; i<5; i++) {
			arr[i] = sc.nextInt();
			if (arr[i] == 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