\problemname{Early Orders}

\illustration{0.3}{perfectflush.png}{}

\noindent
You are given a list of integers $x_1, x_2, \ldots, x_n$ and a number $k$.
It is guaranteed that each $i$ from $1$ to $k$ appears in the list at least once.

Find the lexicographically smallest subsequence of $x$ that contains
each integer from $1$ to $k$ exactly once.

\section*{Input}

The first line will contain two integers $n$ and $k$, with
$1\le k\le n\le 200\,000$.
The following $n$ lines will each contain an integer $x_i$ with
$1\le x_i\le k$.

\section*{Output}

Write out on one line, separated by spaces, the lexicographically smallest
subsequence of $x$ that has each integer from $1$ to $k$ exactly once.

\section*{Examples}
