Problem:
Score : 100 points

Problem Statement

The door of Snuke's laboratory is locked with a security code.

The security code is a 4-digit number. We say the security code is hard to enter when it contains two consecutive digits that are the same.

You are given the current security code S. If S is hard to enter, print Bad; otherwise, print Good.

Constraints

S is a 4-character string consisting of digits.

Input

Input is given from Standard Input in the following format:

S

Output

If S is hard to enter, print Bad; otherwise, print Good.

Sample Input 1

3776

Sample Output 1

Bad

The second and third digits are the same, so 3776 is hard to enter.

Sample Input 2

8080

Sample Output 2

Good

There are no two consecutive digits that are the same, so 8080 is not hard to enter.

Sample Input 3

1333

Sample Output 3

Bad

Sample Input 4

0024

Sample Output 4

Bad

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

use std::io;

macro_rules! get {
    ($t: ty) => {
        {
            let mut x = String::new();
            io::stdin().read_line(&mut x).ok();
            x = x.trim_right().to_owned();
            x.parse::<$t>().unwrap()
        }
    };
    ($($t: ty), *) => {
        {
            let mut x = String::new();
            io::stdin().read_line(&mut x).ok();
            x = x.trim_right().to_owned();
            let mut inter = x.split_whitespace();
            (
                $(inter.next().unwrap().parse::<$t>().unwrap(),)*
            )
        }
    };
}

macro_rules! insert_vec {
    ($t: ty) => {
        {
            let mut x = String::new();
            io::stdin().read_line(&mut x).ok();
            x = x.trim_right().to_owned();
            x.split_whitespace().map(|x| x.parse::<$t>().unwrap())
                .collect::<Vec<_>>()
        }
    };
}

macro_rules! word_chars_vec {
    () => {
        {
            let mut x = String::new();
            io::stdin().read_line(&mut x).ok();
            x = x.trim_right().to_owned();
            x.chars().collect::<Vec<_>>()
        }        
    };
}
fn main() {
    let s = word_chars_vec!();
    if s[0] == s[1] || s[1] == s[2] || s[2] == s[3] {
        println!("Bad");
    } else {
        println!("Good");
    }

}