import java.util.*;
public 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();
      if(a==0){
        System.out.println(1);
      }else if(b==0){
        System.out.println(2);
      }else if(c==0){
        System.out.println(3);
      }else if(d==0){
        System.out.println(4);
      }else 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