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: ['7683', '3657', 'z', 'm', 'E', '5767', '371', 'j', '4623', 'y', 'Z', 'p', '7663', '5493', '7917', 'U']

7683, 3657, 26, 13, 5, 5767, 371, 10, 4623, 25, 26, 16, 7663, 5493, 7917, 21