function Main(input){
  var inp = input.trim().split('\n');
  var N = parseInt(inp[0].trim());
  var S = inp[1].split(' ');

  var answer = 'Three';
  for(var i = 0; i < S.length; i++){
    if (S[i] === 'Y'){
      answer = 'Four';
    }
  }
  console.log(answer);
}
Main(require('fs').readFileSync('/dev/stdin', 'utf8'));
