The solution is as follows. You may accept the invitation to "try to do
it in twenty moves," but you will never succeed in performing the feat.
The fewest possible moves are twenty-six. Play the cars so as to reach
the following positions:--
E5678
-------- = 10 moves.
1234
E56
-------- = 2 moves.
123 87 4
56
-------- = 5 moves.
E312 87 4
E
-------- = 9 moves.
87654321
Twenty-six moves in all.