#!ruby -pl _=o=[] gsub(/./){x=86%$&[0]&67 _+=[x<4?[0,1].map{|i|x-i>o.pop&66?"(#{_.pop})":_.pop}.reverse*$&:$&] o<<x} $_=_
Note that non-ascii characters in the above source code will be escaped (such as \x9f).
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