"use strict";

function main(input) {
  input = input.split(/\n/);
  const n = input[0];
  input = input[1].split(" ");

  let ans = "Three";
  for (let v in input) {
    if (input[v] == "Y") {
      ans = "Four";
      break;
    }
  }

  console.log(ans);
}

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