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: ['f', 'o', '3911', 'f', 'Y', '1199', '7959', '5407', 'e', 'l', 'N', '7509', '5903', 's', 'e', 'l', 'Z', 'K', '7637', 'S', '8123', '9155', '915', '115', '3115', '9635', 'q', '6045', '8557', '6579']

6, 15, 3911, 6, 25, 1199, 7959, 5407, 5, 12, 14, 7509, 5903, 19, 5, 12, 26, 11, 7637, 19, 8123, 9155, 915, 115, 3115, 9635, 17, 6045, 8557, 6579