R>/D,----------/D++++++++++.----------<<<<<<<<D
U<< <<<<<<<<<<<< <<<<<<<<<<<<<<<<<<<<<<<<<<<<<L
   ,D-----------L
U.+LR-----------/D++++++++++++++++++++++++ D
U---------------- ----------------.++++++++L                       D>.++++++++++++++++ L
 D---------------L
 R----------------------------/D+++++++++++++++++++++++++++++++++.>R/U+++++++++++++++++U
U.+++++++++++++++++++++++++++++L