function myout(text){console.log(text);}//standard output
function Main(input) {
	//input = parseInt(input);
	//input = input.trim().split(" ");
	input = input.trim().split("\n");
	//input = input.trim().split(" ").map((a)=>Number(a));
	//input = input.trim().split("\n").map((a)=>Number(a));
  var list = input[1].split(" ");
  if(list.indexOf("Y") != -1){
     myout("Four");
     }else{
       myout("Three");
     }
}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());
