We are given two strings, A and B.

A shift on A consists of taking string A and moving the leftmost character to the rightmost position. For example, if A = 'abcde', then it will be 'bcdea' after one shift on A. Return True if and only if A can become B after some number of shifts on A.

Example 1:

Input: A = 'abcde', B = 'cdeab'

Output: true

Example 2:

Input: A = 'abcde', B = 'abced'

Output: false

Note:

• A and B will have length at most 100.

class Solution(object):

    def rotateString(self, A, B):

        """

        :type A: str

        :type B: str

        :rtype: bool

        """

        if A and B:

            if len(A)!=len(B):

                return False

            for i in range(len(A)):

                if A[i+1:]+A[:i+1]==B:

                    return True

            return False

        if A and B=="":

            return False

        if A=="" and B:

            return False

        return True