Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['8315', '3189', 'j', 'n', 't', 'U', '4163', 'z', '4013', '3159', '8169', '8649', '431', '6291', '1107', '9565', 'm', '1835', '3']

8315, 3189, 10, 14, 20, 21, 4163, 26, 4013, 3159, 8169, 8649, 431, 6291, 1107, 9565, 13, 1835, 3