local function split(text, delimiter)
   if text.find(text, delimiter) == nil then
     return { text }
   end

   local splited_texts = {}
   local last_position

   for splited_text, position in text:gmatch("(.-)"..delimiter.."()") do
     table.insert(splited_texts, splited_text)
     last_position = position
   end
   table.insert(splited_texts, string.sub(text, last_position))
   return splited_texts
end

local total = io.read()
local arares = io.read()

local color = {}
color["p"] = 0
color["w"] = 0
color["g"] = 0
color["y"] = 0

local arare_list = split(arares, " ")
for k,v in pairs(arare_list) do
  if v == "P" then
    color["p"] = color["p"] + 1
  elseif v == "W" then
    color["w"] = color["w"] + 1
  elseif v == "G" then
    color["g"] = color["g"] + 1
  elseif v == "Y" then
    color["y"] = color["y"] + 1
  end
end

local number = 0
if color["p"] > 0 then
 number = number + 1
end
if color["w"] > 0 then
 number = number + 1
end
if color["g"] > 0 then
 number = number + 1
end
if color["y"] > 0 then
 number = number + 1
end

if number == 3 then
  print("Three")
elseif number == 4 then
  print("Four")
end