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: ['a', '851', '6977', '5139', 'E', '6757', '5803', 'P', '609', '6077', 'X', '6151', 'Q', 'n', 's', 'F', '1597']

1, 851, 6977, 5139, 5, 6757, 5803, 16, 609, 6077, 24, 6151, 17, 14, 19, 6, 1597