Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a number chosen from [1,10​4​​]. The first one who bets on a unique number wins. For example, if there are 7 people betting on { 5 31 5 88 67 88 17 }, then the second one who bets on 31 wins.

Input Specification:

Each input file contains one test case. Each case contains a line which begins with a positive integer N (≤10​5​​) and then followed by N bets. The numbers are separated by a space.

Output Specification:

For each test case, print the winning number in a line. If there is no winner, print None instead.

Sample Input 1:

7 5 31 5 88 67 88 17

Sample Output 1:

31

Sample Input 2:

5 888 666 666 888 888

Sample Output 2:

None

1 package pattest; 2  3 import java.io.BufferedReader; 4 import java.io.IOException; 5 import java.io.InputStreamReader; 6 import java.util.ArrayList; 7 import java.util.List; 8  9 /**10  * @Auther: Xingzheng Wang11  * @Date: 2019/2/22 13:5112  * @Description: pattest13  * @Version: 1.014  */15 public class PAT1041 {16     public static void main(String[] args) throws IOException {17         BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));18         String[] sp = reader.readLine().split(" ");19 20         List
     
       list1 = new ArrayList<>();21         List
      
        list2 = new ArrayList<>();22         for (int i = 1; i < sp.length; i++) {23             if (list1.contains(sp[i])){24                 list2.add(sp[i]);25             }else{26                 list1.add(sp[i]);27             }28         }29         list1.removeAll(list2);30         if (list1.size() > 0){31             System.out.print(list1.get(0));32         }else{33             System.out.print("None");34         }35     }36 }