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: ['6739', 't', 'r', '8717', '759', 'a', '6701', 'd', 'b', '3003', 'x', 'x', '4787', '487', 'M', 'q', 'B', 'D', 'u', 'm', '5477', 'l', '4725', 'O', '6883', '2917', '509', '9873', '8023', 'M', '2743', 'T', 'W', 'Z']

6739, 20, 18, 8717, 759, 1, 6701, 4, 2, 3003, 24, 24, 4787, 487, 13, 17, 2, 4, 21, 13, 5477, 12, 4725, 15, 6883, 2917, 509, 9873, 8023, 13, 2743, 20, 23, 26