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: ['H', 'W', 'X', 'x', 'c', '1295', '2339', 'l', '2835', '1663', 'H', '261', 'o']

8, 23, 24, 24, 3, 1295, 2339, 12, 2835, 1663, 8, 261, 15