import java.util.Scanner

object Main {
  def main(args: Array[String]): Unit = {
    val sc = new Scanner(System.in)
    val n = sc.nextInt()
    var f = false
    for(i <- 0 until n) {
      val ch = sc.next()
      if(ch.equals("Y")) {
        f = true
      }
    }
    if(f) {
      println("Four")
    } else {
      println("Three")
    }
  }
}
