Find the Difference

Problem Statement:

Given two strings s and t which consist of only lowercase letters.
String t is generated by random shuffling string s and then add one more letter at a random position.
Find the letter that was added in t.

Example:
Input:
s = "abcd"
t = "abcde"

Output:
e

Explanation:
'e' is the letter that was added.


Solution:
class Solution(object):
    def findTheDifference(self, s, t):
        for i in set(t):
            if s.count(i)!=t.count(i):
                return i