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: ['47', 'G', 'M', '2721', 'u', '3301', 'p', '1407', '4261', 'Z', '6921', 'g', '1685', '4497', '7189']

47, 7, 13, 2721, 21, 3301, 16, 1407, 4261, 26, 6921, 7, 1685, 4497, 7189