题解 | 好串
好串
https://www.nowcoder.com/practice/9b072237ebdd4dd99562f01cbf594fac
s=input()
l=[]
for i in s:
if i=='a':
l.append(i)
elif i=='b':
if len(l)==0:
l.append(i)
elif len(l)>0 :
if l[-1]=='a':
l.pop()
if not l:
print('Good')
else:
print('Bad')
