In the deck, Gromozeka has cards on which one whole number is written. Each number in the deck occurs exactly 4 times.
Thus, in the deck there are 4 cards with the number 1, 4 cards with the number 2, ..., 4 cards with the number
N. In total, there are
4*N cards in the code.
Gromozeka shuffled those cards, then hid one of them and gave you a stack of the remaining
4*N-1 cards. The
i-th card (1<= i <=4*N−1) from the stack contains an integer
Ai.
Find the integer written on the card that Gromozeka hid.
Input
The program receives two lines as input. The first line contains the integer
N (1 <= N <= 10
5). The second line contains
4*N-1 integers
Ai (1 <= Ai <= 4*N−1. 1<= i <=4*N−1). For each
k (1<=k<=N) there are at most 4
i indices, such that
Ai=k.
Imprint
Print the answer to the problem.
Examples
| # |
Input |
Output |
| 1 |
3
1 3 2 3 3 2 2 1 1 1 2
| 3 |
| 2 |
1
1 1 1
| 1 |
| 3 |
4
3 2 1 1 2 4 4 4 4 3 1 3 2 1 3
| 2 |