import java.util.*;

class Main
{
    public static void main(String[] args)
    {
        int x=-1, k=-1;
        Scanner input = new Scanner(System.in);
        for(int i=1; i<=5; i++){
            x=input.nextInt();
            if(x==0){
                k=i;
            }
        }
        System.out.print(k);
    }
}
/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