to csv.data.manipulation :in :out
    local [header line list sum]
   openread :in
   setread :in
   openwrite :out
   setwrite :out
   make "header readword
    print word :header ",SUM
   while  [not eofp] [
      make "line readword
      make "list parse map [ifelse equalp ? ", ["\ ] [?]] :line
      make "sum apply "sum :list
      print (word :line "\, :sum)
   ]
   close :in
   setread []
   close :out
   setwrite []
end