File standardInput readLines map(split slice(1))do(o:=list
f:=method(map(i,v,if(v,atPut(i,v=v difference(o))if(v size<1,atPut(i)o push(""..(i+1)println);f))))
f)
Note that non-ascii characters in the above source code will be escaped (such as \x9f).