Question 80
On a computer screen is the single character $a$. The computer has two keys: $c$ (copy) and $p$ (paste), which may be pressed in any sequence.
Pressing $p$ increases the number of $a$'s on screen by the number that were there the last time $c$ was pressed. $c$ doesn't change the number of $a$'s on screen. Determine the fewest number of keystrokes required to attain at least $2018$ $a$'s on screen. (Note: pressing $p$ before the first press of $c$ does nothing).
Pressing $p$ increases the number of $a$'s on screen by the number that were there the last time $c$ was pressed. $c$ doesn't change the number of $a$'s on screen. Determine the fewest number of keystrokes required to attain at least $2018$ $a$'s on screen. (Note: pressing $p$ before the first press of $c$ does nothing).