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: ['4297', 'H', 'B', '1281', '7127', '6351', '2227', 'W', 'Y', 'B', '3557', '2509', '827', 'H', '7651', '147', '6111', 'y', 'u', '5685', '2709', 'n', '1467', '59', '1073', 'T', '3215', 'c', '6729', '4223', 'k', 'z']

4297, 8, 2, 1281, 7127, 6351, 2227, 23, 25, 2, 3557, 2509, 827, 8, 7651, 147, 6111, 25, 21, 5685, 2709, 14, 1467, 59, 1073, 20, 3215, 3, 6729, 4223, 11, 26