Tag or the game of 15 is a well-known game from the puzzle series. The number 15 in the name of the game comes from the number of pictures enclosed in the box. In total, there are 16 cells in the box, one of which is not occupied by the picture. The size of the box is 4x4. The player can move the pictures in the box due to the free cell. The goal of the game is to collect pictures so that the main photo card is located on the right, using as few moves as possible. The game is considered completed as soon as the goal is reached.