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: ['1621', '1301', 'r', '1575', '1445', 's', 'v', 'S', '9027', '8549', 'I', '8783', 'D', '621', 'N', 'r', 'S', '9643', '4415', 'h', '4209', '4421']

1621, 1301, 18, 1575, 1445, 19, 22, 19, 9027, 8549, 9, 8783, 4, 621, 14, 18, 19, 9643, 4415, 8, 4209, 4421