18 24 O.X.XX.....X....X....X.. .O...X..X.O....O....O.O. X.........X..O..O..X...X ..X.....X...X......X.... .....O.X.O..X.X..O...... O..XX.O....O....X....XO. ...........X........XX.X .X.X..X.O........O..X..X ..........X.O.X..O.O.... .O..XX.O................ ..X......O...XX......... ...O....OO.O..OO.X...... O.....O....O.......O.... O...XX....X......X.O.... .OO....OO.....XX......O. .........XO..X....O..X.. ..OO.OO....O....O...O..O O..............OX......X