import java.util.*;
public class Main { 
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int o=0;
        
        for(int i=1;i<=5;i++){
            int x=sc.nextInt();
          if(x==0)o=i;
          	
        }
      System.out.println(o);
    }
    
}
/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