(#1=dotimes(i(set'n(ash 1(read))))(format t"~&~V@T"(- n i 1))(#1#(j(1+ i))(princ(if(#2=oddp(/(! i)(! j)(!(- i j))))(if(#2#i)(if(#2#j)"_\\"'/_)"/\\")"  "))))