James is sharing his information with his friend secretly in a chat. But he thinks that message should not understandable to anyone only for him and his friend. So he sent the message in the following format. Input a1b2c3d4e Output abbdcfdhe Explanation: The digits are replaced as follows: - s[1] -> shift('a',1) = 'b' - s[3] -> shift('b',2) = 'd' - s[5] -> shift('c',3) = 'f' - s[7] -> shift('d',4) = 'h'.