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: ['F', 'T', '3039', '6349', '4619', 'P', 'B', 't', 'x', '2115', 'F', '4247', '5685', 'P', 'o', '3431', '3217', 'O', 'P', '2181', '6459', '2415', 'z']

6, 20, 3039, 6349, 4619, 16, 2, 20, 24, 2115, 6, 4247, 5685, 16, 15, 3431, 3217, 15, 16, 2181, 6459, 2415, 26