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: ['5991', 'F', 'y', '8053', '7979', '2785', 'u', 'O', 'S', '7939', '215', 'M', '6099', '305', '3369', 'b', '5371', '7423', 'H', 'Q', 'h']

5991, 6, 25, 8053, 7979, 2785, 21, 15, 19, 7939, 215, 13, 6099, 305, 3369, 2, 5371, 7423, 8, 17, 8