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', 'k', '2677', '9645', 'd', '8145', 'n', '6313', 'Y', 'V', 'u', '1311']

8, 11, 2677, 9645, 4, 8145, 14, 6313, 25, 22, 21, 1311