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: ['4883', '9823', '6519', 'P', 'Q', '8265', 'G', '7129', '6847', '555', 'f', '609', '3851', 'u', '8677', '7867', 'o', '4385', '5091', 'B', 'D', 'W', '2175']

4883, 9823, 6519, 16, 17, 8265, 7, 7129, 6847, 555, 6, 609, 3851, 21, 8677, 7867, 15, 4385, 5091, 2, 4, 23, 2175