content: package thaw;
  
  import java.util.*;
  import java.io.*;
  
  public class Thaw {
      private static ArrayList<String> data = new ArrayList<>();
      private static ArrayList<Integer> temp = new ArrayList<>();
      private static ArrayList<Integer> tempPlus = new ArrayList<>();
      private static void getData() throws IOException{
          FileReader file = new FileReader("input.txt");
          Scanner sc = new Scanner(file);
          while (sc.hasNextLine()){
              data.add(sc.nextLine());
          }
          StringTokenizer st = new StringTokenizer(data.get(1), " ");
          while (st.hasMoreTokens()){
              temp.add(Integer.valueOf(st.nextToken()));
          }
      }
      public static void main(String[] argv) throws IOException{
          getData();
          int j = 0;
          for(Integer i : temp){
              if(i > 0){
                  j++;
              }else{
                  tempPlus.add(j);
                  j = 0;
              }
          }
          tempPlus.add(j);
          tempPlus.sort(Collections.reverseOrder());
          String result = (!tempPlus.isEmpty()) ? String.valueOf(tempPlus.get(0)) : "0";
          PrintWriter pw = new PrintWriter(new File("output.txt"));
          pw.print(result);
          pw.close();
      }
  }
  