Problem:
Score : 200 points

Problem Statement

In Japan, people make offerings called hina arare, colorful crackers, on March 3.

We have a bag that contains N hina arare. (From here, we call them arare.)

It is known that the bag either contains arare in three colors: pink, white and green, or contains arare in four colors: pink, white, green and yellow.

We have taken out the arare in the bag one by one, and the color of the i-th arare was S_i, where colors are represented as follows - pink: P, white: W, green: G, yellow: Y.

If the number of colors of the arare in the bag was three, print Three; if the number of colors was four, print Four.

Constraints

1 \leq N \leq 100

S_i is P, W, G or Y.

There always exist i, j and k such that S_i=P, S_j=W and S_k=G.

Input

Input is given from Standard Input in the following format:

N
S_1 S_2 ... S_N

Output

If the number of colors of the arare in the bag was three, print Three; if the number of colors was four, print Four.

Sample Input 1

6
G W Y P Y W

Sample Output 1

Four

The bag contained arare in four colors, so you should print Four.

Sample Input 2

9
G W W G P W P G G

Sample Output 2

Three

The bag contained arare in three colors, so you should print Three.

Sample Input 3

8
P Y W G Y W Y Y

Sample Output 3

Four

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::env;
use std::io::*;
use std::str::*;
use std::mem;
use std::collections::HashMap;

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let s = stdin.bytes().map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    s.parse::<T>().ok().unwrap()
}
fn read_char() -> char {
    let c = read::<String>();
    let c = c.chars().collect::<Vec<char>>();
    c[0]
}
fn read_String_Vec() -> Vec<char> {
    let S = read::<String>();
    S.chars().collect::<Vec<char>>()
}

fn vecchar_to_String(Vs: &Vec<char>) -> String {
    let mut S = String::new();
    for i in 0..Vs.len() {
        S.push(Vs[i]);
    }
    S
}

/*
A : 65
Z : 90
a : 97
z : 122
*/

/*
let N = read::<i32>();
let S = read::<String>();
let S = read_String_Vec();
let C = read_char();
*/

/*
 .to_string() : * -> String
 &*S          : String -> &str
*/

fn main() {
    // main の引数
    /*
        引数なしのときargs.len() = 1;
    */
    let args: Vec<String> = env::args().collect();

    let N = read::<usize>();
    let mut Four = false;
    for n in 0..N {
        let C = read_char();
        if C == 'Y' {
            Four = true;
        }
    }

    if Four {
        println!("Four");
    } else {
        println!("Three");
    }
}