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: ['I', 'Z', 'l', 'A', '2841', 'h', 'W', 'g', '5123', '5823', 'K', 'u', 'p', 'L']

9, 26, 12, 1, 2841, 8, 23, 7, 5123, 5823, 11, 21, 16, 12