let () =
  let chk = Array.make 4 0 in
  Scanf.scanf "%d" (fun n -> Array.init n (fun _ -> Scanf.scanf " %c" (String.index "PWGY")))
  |> Array.iter (fun x -> chk.(x) <- 1);
  Array.fold_left (+) 0 chk |> (fun x -> if x = 3 then "Three" else "Four")
  |> print_endline