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: ['587', 'd', 'Q', '5243', '4731', 'S', '2167', '8321', '4603', '677', 'D', '5255', 'c', '1533', '759', '4063', 'J']

587, 4, 17, 5243, 4731, 19, 2167, 8321, 4603, 677, 4, 5255, 3, 1533, 759, 4063, 10