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: Wrong Answer)

use std::io;

fn main(){
    let mut s = String::new();
    io::stdin().read_line(&mut s).expect("");
    let c : Vec<char> = s.chars().collect();
    let mut f = true;
    for i in 0..2{
        if c[i] == c[i + 1]{
            f = false;
        }
    }
    let ans = if f {"Yes"} else {"No"};
    println!{"{}", ans};
}