import std.stdio;
import std.string;
import std.conv;

int main() {
  int[string] hash;
  int n = to!int(readln.chomp);
  string[] s = readln.chomp.split;

  foreach (ref c; s) {
    hash[c]++;
  }

  writeln(hash.length == 3 ? "Three" : "Four");

  return (0);
}
