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: ['6839', '7817', 'R', '2107', 'k', 'd', 'd', '881', '9919', '6181', 'Z', 'Q', '7585', '2067']

6839, 7817, 18, 2107, 11, 4, 4, 881, 9919, 6181, 26, 17, 7585, 2067