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: Runtime Error)

use std::env;  

fn main() {
    //let mut buf=read::<String>();
    let mut args: Vec<String> = env::args().collect();
    //println!("{}", args[1]);

    let pass = &args[1];


    //let mut buf = 

    let mut buf = '\0';
 
    for i in pass.as_str().chars() {
        if i == buf {
            print!("Bad\n");
            return();
        }else{
            buf = i;
        }
    }
    print!("Good\n");
    
}