import java.util.*;
class Main{
  static Scanner sc = new Scanner(System.in);
  public static void main(String[] args){
    int x[] = new int[9999999];
    for(int i=0;i<5;i++){
      x[sc.nextInt()]=i;
    }
    System.out.println(x[0]+1);
  }
}
/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