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: ['2675', '5385', 'R', '1615', 'Z', '7895', 'p', 'X', 'U']

2675, 5385, 18, 1615, 26, 7895, 16, 24, 21