Instruction for tic tac toe :--

• The game is played on a grid that's 3 squares by 3 squares.
• You are X, your friend is O. Players take turns putting their marks in empty squares.
• The first player to get 3 of her marks in a row (up, down, across, or diagonally) is the winner.
• When all 9 squares are full, the game is over.