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

void main() {
	int N = to!(int)(readln().chomp());
	string [] S = readln().chomp().split();
	bool flg = false;
	foreach(i; S) {
		if(i=="Y")
			flg = true;
	}
	if(flg)
		writeln("Four");
	else
		writeln("Three");
}
