A group of children gathered on the playground and decided to while away their time playing mahjong puzzle. You in the game Playground Mahjong will take part in this entertainment. In front of you on the screen you will see the playing field, which will be filled with tiles. You will see a drawing on each tile. You will need to examine everything very carefully. Find tiles with two identical images. Now you will have to select them with a mouse click. Thus, you will remove these items from the playing field and get points for this. Your task is to clear the playing field of all tiles in the shortest possible time.