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: ['5831', '7889', 'W', '4657', '85', 'c', 'k', '773', 'M', '3665', '2989', '9475', 'B', '6253', 'e', 'K', 'O', '5785']

5831, 7889, 23, 4657, 85, 3, 11, 773, 13, 3665, 2989, 9475, 2, 6253, 5, 11, 15, 5785