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: ['c', 'i', 't', 'c', '4749', 'K', 's', '5123', 'W', 'h', '1805', 'q', 'L', 'O', '1435', 'Y', '3971', 'S', '7887', '2907', 'Q', '915', 'k', 'V', '8339', 'u', '8121', 'O']

3, 9, 20, 3, 4749, 11, 19, 5123, 23, 8, 1805, 17, 12, 15, 1435, 25, 3971, 19, 7887, 2907, 17, 915, 11, 22, 8339, 21, 8121, 15