Problem Statement

You, a competitive programmer, have been asked by your friend 31536000 to act as a tester for a problem.
The problem is as follows.

$3$ values are given.
Among the values that can be obtained by adding $2$ of them, output the $2$-nd largest.

After reading this problem, you immediately wrote code and submitted it, but it fails on only some of the cases.
Puzzled, you checked the test cases and found that some of them are space-separated rather than newline-separated.
So you decided to output a notice to that effect for the incorrect test cases.

Input

$N$
$A_1$
$\vdots$
$A_N$

・$N = 3$
・$1 \leq A_i \leq 10^{10}$
・$A_1 \neq A_N$
・All inputs are given as integers

Output

Among the values that can be obtained by adding 2 of them, output the 2-nd largest.
However, if the input format is
$N$
$A_1$ $\cdots$ $A_N$
then output "assert" instead.
In either case, end the output with a newline.
Also, in this problem, the 2-nd largest value refers to the value that is second from the largest. (There is no error in test case 2.)

Sample

3
1
5
3

6

3
3
3
4

6

3
1 5 3

"assert"