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: ['M', '7609', 'i', '6419', 'R', 's', 'V', 'c', 'Z', 'f', '2329', 'u', 'H', '8741', '111', 'z', 'W', '3803', 'X', '6489', '5207', 'b', '3551', 'i', 'X', '139', 'x', 'O', '7321', 'y', '3053']

13, 7609, 9, 6419, 18, 19, 22, 3, 26, 6, 2329, 21, 8, 8741, 111, 26, 23, 3803, 24, 6489, 5207, 2, 3551, 9, 24, 139, 24, 15, 7321, 25, 3053