Move 16 panels outside!
Since the panel in which the numbers from 1 to 16 were written is displayed, if it is made to slide to the portion into which the outer frame disappeared from the small number, a panel will disappear. The number made to slide (it becomes a target) is displayed. If all the panels are erased, it will be the end of a game.
Probably, it will be easy since the color of the panel made to slide to the next changes on the level 1. On the level 3, it is that in which two outer frames have disappeared (one is a dummy), Lets make it not confused.
It is enclosed by the panel of a surrounding large number depending on arrangement of a number, and when the most, it cannot necessarily erase from a small number. Please erase from "the smallest possible number."