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: ['7939', 'o', '9869', '8571', '8535', '6973', '8107', 'F', '3151', '3185', 'I', '641', '8483', 'v', '3639', 'S', '549', 'G', 'l', '1681', 'i', '2621', 't', '2189', 'f', '3851', 'K', '6893']

7939, 15, 9869, 8571, 8535, 6973, 8107, 6, 3151, 3185, 9, 641, 8483, 22, 3639, 19, 549, 7, 12, 1681, 9, 2621, 20, 2189, 6, 3851, 11, 6893