\problemname{Hot Springs}
\providecommand{\maxn}{}
\renewcommand{\maxn}{10^5}
\providecommand{\maxa}{}
\renewcommand{\maxa}{10^5}

\illustration{0.35}{hotsprings.jpg}{\href{https://unsplash.com/photos/cRiUOdL0pkI}{Blue Lagoon} by Andy Wang, Unsplash}%
Iceland is famous for its geothermal activity, which supplies the country with much of its
electricity and heating. It is also a source of pleasure, in the form of hot springs.

Kalle is visiting one of Iceland's famous hot springs. It contains $n$ pools of water, 
where the $i$th one has temperature $t_i$. Although staying in one of the warmer pools 
for a long time sure is relaxing, Kalle is on a very tight schedule and just wants a quick
dip in each of the pools. As you may know, the nicest thing about hot baths is the contrast
between hot and cold. Therefore, to get the most out of his stay, Kalle wants to find an ordering
of the pools so that the difference in temperature between subsequent pools is increasing.

Given a sequence of pool temperatures $t_1, t_2, \dots, t_n$, rearrange them into a new sequence
$t'_1, t'_2, \dots, t'_n$ such that for all $2 \leq i \leq n-1$ it holds that
\[
    |t'_{i-1} - t'_i| \leq |t'_i - t'_{i+1}|.
\]

\begin{Input}
The input consists of:

\begin{itemize}
\item One line with an integer $n$ ($2 \le n \leq  10^5$), the number of pools.
\item One line with $n$ integers $t_1, \ldots, t_n$ ($-\maxa \leq t_i \leq \maxa$ for each $i$), the
    temperatures in each of the $n$ pools.
\end{itemize}

\end{Input}

\begin{Output}
Output a rearrangement of the sequence satisfying the given requirement.
If no solution exists, output ``\texttt{impossible}''. If there are multiple
valid solutions, you may output any one of them.
\end{Output}

