function main(input) {
 a = "Good";

 if (S[0] == S[1]){
  a = "bad";
 }

else if ( S[1] == S[2]){
 a = "bad"; 
}
else  if ( S[2] == S[3]){
 a = "bad";
}
else{
	a = "Good"
}
console.log(a)

}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));