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i:{{((c"RDLU"?*x;.y;c@16!z;-16!z:16/39!-48+z))}." "\x^"()#"}'0:"i/18"

f:{
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 m:m{$[**y;(1 0;-1 0);0]+x@<x:(x;x+*/2#y)}'x

 hor:+m[;;0]
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 h:|1,|1_{x-y}':h

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  }'x,'(():':x),'|():':|x
 }[;s]/(~!#s)#'s

 +/x[;1],/h*{1+y-x}.''s2}

f@i[;0 1]
f@i[;2 3]