import java.util.Scanner;

public class Main {
public static void main(String[] args) {
	Scanner scn=new Scanner(System.in);
	int []arr=new int [5];
	int ans=0;
	for(int i=0;i<5;i++) {
		arr[i]=scn.nextInt();
		if(arr[i]==0)
			ans=i+1;
	}
	System.out.println(ans);
}
}

/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