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: ['J', 'a', 'c', 'v', '7489', 'l', '9043', '6579', '2821', 't', '7411', '7143', '5843', '251', 'k', 'U', '9811', 'n', 'p', 'J', '6071', 'b', 'Q', '4231', 'g', 'K', '9665', '4255', 't', 'n', 'W', 'N']

10, 1, 3, 22, 7489, 12, 9043, 6579, 2821, 20, 7411, 7143, 5843, 251, 11, 21, 9811, 14, 16, 10, 6071, 2, 17, 4231, 7, 11, 9665, 4255, 20, 14, 23, 14