1.〜4. ____________________________________ |←←←●            | |        □       | |  ●→→→→→→→●   ● L___| |●             ↑ ↑ | |   |~~~~~~~~~~~~~~~~~~~~|↑ ↑ | |   |          |↑ ● | |   |          |●   | | ● |          |    | |   |          |    | :   :          :    : 5.〜6. ____________________________________ |●             ↑ | |        □     ↑ | |         ●●   ● L___| |●←←←←←←←←←←←←←● ● | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 7. ____________________________________ |●←←←←←←←←←←←←←● | |        □       | |         ●●     L___| |●●              ● | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 8. ____________________________________ |●●              | | ↑      □       | | ↑       ●●     L___| |●●              ● | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 9. ____________________________________ |●●              | | ●      □       | |         ●●     L___| |●←←←←←←←←←←←←←←←● | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 10. ____________________________________ |●●              | | ●      □       | |         ●●     L___| |●●                | |↓  |~~~~~~~~~~~~~~~~~~~~|    | |↓  |          |    | |↓  |          |    | |↓● |          |    | |↓  |          |    | :↓  :          :    : 11. ____________________________________ |●●              | | ●      □       | | ↑       ●●     L___| | ●                | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 12. ____________________________________ |●●              | | ●      □       | | ●→→→→→→→●●     L___| |                  | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | | ● |          |    | |   |          |    | :   :          :    : 13.〜14. ____________________________________ |●●      ↑       | | ●      ↑       | | ↑      ●●●     L___| | ↑                | | ↑ |~~~~~~~~~~~~~~~~~~~~|    | | ↑ |          |    | | ↑ |          |    | | ● |          |    | |   |          |    | :   :          :    : 15. ____________________________________ |●●      ●       | | ●      □       | | ●→→→→→→→●●     L___| |                  | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | |   |          |    | |   |          |    | :   :          :    : 16. ____________________________________ |●●      ●       | | ●      ↑       | |        ●●●     L___| |                  | |   |~~~~~~~~~~~~~~~~~~~~|    | |   |          |    | |   |          |    | |   |          |    | |   |          |    | :   :          :    :