public class Solution    {        public bool RotateString(string A, string B)        {            string temp = A;            int len = A.Length;            int lenB = B.Length;            if (len != lenB)            {                return false;            }            if (len == 0)            {                return true;            }            for (int i = 0; i < len; i++)            {                var prefix = A.Substring(0, i);                var next = A.Substring(i);                if (B.Equals(next + prefix))                {                    return true;                }            }            return false;        }    }