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: ['E', '7671', 'D', '9553', '1539', '4661', '5961', 'a', 'W', '8603', 'f', '767', '7333', 'u', 'Q', 's', 'u', 'T', 'p', '3959', 'p', '1233', 'P', '7923', 'K', '9691', 'D', '1129', '1923']

5, 7671, 4, 9553, 1539, 4661, 5961, 1, 23, 8603, 6, 767, 7333, 21, 17, 19, 21, 20, 16, 3959, 16, 1233, 16, 7923, 11, 9691, 4, 1129, 1923