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.
Q: ['8391', 'c', '7843', 'O', 'Q', '7639', 'Y', '9649', 'd', 'H', '5233', '3107', '2521', '6655', '4629', '1595', '5857', '143', '6817', '227', 't', '9429', 'w', '1215', '387']
A: 
8391, 3, 7843, 15, 17, 7639, 25, 9649, 4, 8, 5233, 3107, 2521, 6655, 4629, 1595, 5857, 143, 6817, 227, 20, 9429, 23, 1215, 387