import std.stdio;
import std.conv;
import std.algorithm;
import std.string;
import std.array;

void main() {
    int n = readln.chomp.to!int;
    auto s = readln.chomp.split;

    bool[string] dict;
    int ans;

    foreach(ss; s) {
        if ((ss in dict) is null) {
            dict[ss] = true;
            ans++;
        }
    }

    if (ans == 3) {
        writeln("Three");
    }
    else {
        writeln("Four");
    }

    return;
}