Concentration is played by two players (human and/or computer). The game starts with all 52 cards in the deck being placed face down on the play area. Player One begins the game by flipping any two cards in the play area. If the two flipped cards match, then those two cards are removed from the play area and the player gains two points and another turn. If the two flipped cards do not match, then the two cards are returned to their original face down positions and it becomes the other player's turn. Once all the cards have been matched the game ends. The player who has the most matches (points) at the end of the game wins. If you plan to keep and/or use this program, Concentration, then you are asked to (but don't have to) donate $5 to someone much less fortunate than yourself.