open System
open System.Collections
open System.Collections.Generic
open System.IO

[<EntryPoint>]
let main _ = 
    let N = Console.ReadLine() |> int
    let S = Console.ReadLine().Split() |> seq
    
    let ans =
        let cnt = S |> Seq.distinct |> Seq.length
        if  cnt = 3 then
            "Three"
        else 
            "Four"

    printfn "%s" ans
    
    0

