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