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: ['6437', 'u', '8131', 'F', '2901', 'C', '7497', 'a', 'B', '9877', '6933', 'A', '1293', '1403', '2585', '2397', '2173', '2661', 'o', 'A', 'J', 'j', 'o', 'P', '7917', '6229', '1415', 'Q', '9839', 'C', '6677', 'f', 'c', 'v', 'j', '5245', '4989', '6949', 'T']

6437, 21, 8131, 6, 2901, 3, 7497, 1, 2, 9877, 6933, 1, 1293, 1403, 2585, 2397, 2173, 2661, 15, 1, 10, 10, 15, 16, 7917, 6229, 1415, 17, 9839, 3, 6677, 6, 3, 22, 10, 5245, 4989, 6949, 20