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, 10⁴]. 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 (<=10⁵) 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.

7 5 31 5 88 67 88 17

31

5 888 666 666 888 888

None

 1 #include<stdio.h>
 2 #include<math.h>
 3 #include<stdlib.h>
 4 #include<string.h>
 5 #include<algorithm>
 6 using namespace std;
 7 
 8 int main()
 9 {
10     int bet[100010], hashtable[10010] = {};
11     int n, i, flag = 0, x;
12     scanf("%d", &n);
13     for(i = 0; i < n; i++)
14     {
15         scanf("%d", &bet[i]);
16         x = bet[i];
17         hashtable[x]++;
18     }
19     for(i = 0; i < n; i++)
20     {
21         x = bet[i];
22         if(hashtable[x] == 1)
23         {
24             printf("%d\n", bet[i]);
25             flag = 1;
26             break;
27         }
28     }
29     if(!flag)
30         printf("None\n");
31     return 0;
32 }