Ex23

        public static int LongestPolindrome(string st)
        {
            int maxLength = 0, currentLength;
            int i = 0, nextI, k;
            while (i < st.Length)
            {

                currentLength = 1;
                k = 1;
                nextI = st.IndexOf('*', i);
                if (nextI < 0)
                    nextI = st.Length - 1;
                while (nextI >= k && nextI + k < st.Length && st[nextI - k] == st[nextI + k])
                {
                    k++;
                    currentLength += 2;
                }
                if (currentLength > maxLength)
                    maxLength = currentLength;
                i = nextI + 1;
            }
            return maxLength;
        }