We are given two sentences A and B. (A sentence is a string of space separated words. Each word consists only of lowercase letters.)

A word is uncommon if it appears exactly once in one of the sentences, and does not appear in the other sentence.

Return a list of all uncommon words.

You may return the list in any order.

Example 1:

Input: A = "this apple is sweet", B = "this apple is sour"

Output: ["sweet","sour"]

Example 2:

Input: A = "apple apple", B = "banana"

Output: ["banana"]

Note:

1. 0 <= A.length <= 200
2. 0 <= B.length <= 200
3. A and B both contain only spaces and lowercase letters.

class Solution:    def uncommonFromSentences(self, A, B):        """        :type A: str        :type B: str        :rtype: List[str]        """        dicta = {}        dictb = {}        res = []        for i in A.split(' '):            if i not in dicta:                dicta[i] = 1            else:                dicta[i] += 1        for i in B.split(' '):            if i not in dictb:                dictb[i] = 1            else:                dictb[i] += 1        for key,value in dicta.items():            if value==1 and key not in dictb:                res.append(key)        for key,value in dictb.items():            if value==1 and key not in dicta:                res.append(key)        return res