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: ['s', 'C', 'r', '453', '6119', '1493', '4771', '487', 'z', '4487', 'p', 'a', '5423', '3227', '735', '8755', 't', 'm', 'd', '7449', '1931', 'S', '8147', '8807', 'b', 'L', 'Z', '9469', 'b', '1287', 'l', 'a', '2853']

19, 3, 18, 453, 6119, 1493, 4771, 487, 26, 4487, 16, 1, 5423, 3227, 735, 8755, 20, 13, 4, 7449, 1931, 19, 8147, 8807, 2, 12, 26, 9469, 2, 1287, 12, 1, 2853