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: ['H', '1841', '67', '9121', '5739', 'w', '1289', 'M', '3507', '3327', 'u', 'n', '1907', '6585', '5503', 'E', 'm', '4067', 'g', '5029', 'r', '9697', 'b', 'v', '3821', 'k', '8533', 'r']

8, 1841, 67, 9121, 5739, 23, 1289, 13, 3507, 3327, 21, 14, 1907, 6585, 5503, 5, 13, 4067, 7, 5029, 18, 9697, 2, 22, 3821, 11, 8533, 18