s = input()

def getresult(s):
    stack = []  # 看字符a,b是否能完全配对
    for c in s:
        if c == 'a':
            stack.append(c)
        elif c == 'b':
            if len(stack) > 0 and stack[-1] == 'a':
                stack.pop()
            else:
                return 'Bad'
    return 'Good' if len(stack) == 0 else 'Bad'

print(getresult(s))