
import java.util.*;
 
class Main {
    public static void main(String[] args) {
 	   Scanner sc = new Scanner(System.in);
		int intA = sc.nextInt();
      	int intB = sc.nextInt();
      	int intC = sc.nextInt();
      	int intD = sc.nextInt();
      	int intE = sc.nextInt();
      

      if (intA == 0 ) {
        System.out.println("1");
      } else if (intB == 0){
        System.out.println("2");
      } else if (intC == 0){
        System.out.println("3");
      } else if (intD == 0){
        System.out.println("4");
      } else if (intE == 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