You are given an input list that consists of $n$ numbers. Each integer between $1$ and $n$ appears exactly once in the list.
Your task is to create a sorted output list using two stacks. On each move you can do one of the following:
The first input line has an integer $n$ .
The second line has $n$ integers: the contents of the input list.
Print $n$ integers: for each number the stack where it is moved ( $1$ or $2$ ).
You can print any valid solution. If there are no solutions, print IMPOSSIBLE .