# Whiteboard

$1,\ 2,\ 3,\ 4,\ 5$

These five numbers are written on a whiteboard. You start with a score of 0. You pick two numbers, add their positive differences to your score, and erase your choice of one of the two numbers. This process is repeated until there is only one number left on the whiteboard.

What is the highest score you can get?

For example, if you first pick 1 and 2 and erase 2, your score becomes $2-1=1,$ and only $1,3,4,5$ are left on the whiteboard.

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