```
def getHint(self, secret, guess):
dic = {}
for c in secret:
if c not in dic:
dic[c] = 0
dic[c] += 1
A = 0
B = 0
for i in xrange(len(secret)):
if secret[i] == guess[i]:
A += 1
dic[secret[i]] -= 1
for i in xrange(len(secret)):
if secret[i] != guess[i] and guess[i] in dic and dic[guess[i]]>0:
dic[guess[i]] -= 1
B += 1
return str(A)+'A'+str(B)+'B'
```