It is a free cell which can be done with easy operation.
Just touch the card you want to move.
If there are multiple destinations, repeat the touch until it becomes the desired place.
You can also operate by dragging.
Rules can be placed on one larger card than the number of cards to move.
Also, when stacking cards overlap so that red and white alternate.
You can put your favorite card in the free area. (The place in the upper right can not be piled up)
Finally, I will place the cards in 1 to K order in the upper left area.
If all the cards are gathered in the upper left, it is completion.