CF652B.z-sort

A student of $z$ -school found a kind of sorting called $z$ -sort. The array $a$ with $n$ elements are $z$ -sorted if two conditions hold:

1. $a_{i}>=a_{i-1}$ for all even $i$ ,
2. $a_{i}<=a_{i-1}$ for all odd i>1 .

For example the arrays [1,2,1,2] and [1,1,1,1] are $z$ -sorted while the array [1,2,3,4] isn’t $z$ -sorted.

Can you make the array $z$ -sorted?

The first line contains a single integer $n$ ( $1<=n<=1000$ ) — the number of elements in the array $a$ .

The second line contains $n$ integers $a_{i}$ ( $1<=a_{i}<=10^{9}$ ) — the elements of the array $a$ .

If it's possible to make the array $a$ $z$ -sorted print $n$ space separated integers $a_{i}$ — the elements after $z$ -sort. Otherwise print the only word "Impossible".