let id x = x

let to_class w =
  if w <= 48.0 then "light fly"
  else if w <= 51.0 then "fly"
  else if w <= 54.0 then "bantam"
  else if w <= 57.0 then "feather"
  else if w <= 60.0 then "light"
  else if w <= 64.0 then "light welter"
  else if w <= 69.0 then "welter"
  else if w <= 75.0 then "light middle"
  else if w <= 81.0 then "middle"
  else if w <= 91.0 then "light heavy"
  else "heavy"

let _ =
  try
    while true do
      let w = Scanf.scanf "%f\n" id in
      Printf.printf "%s\n" (to_class w)
    done
  with
    End_of_file -> ()