import scala.io._

object Main {
	def main(args: Array[String]) {
		val input = Source.fromInputStream(System.in)
		val lines = input.getLines.toSeq

		var kindArare = List("P", "Y", "W", "G")
		var arares = lines(1).split(" ")
		var count = 0
		arares.foreach{
			s =>
			kindArare = kindArare.map{
				t =>
				if(s == t) {
					count += 1
					""
				}else{t}
			}
		}
		if (count > 3){
			println("Four")
		}else{
			  println("Three")
		}
	}
}
