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: ['1575', 'x', 'b', 'N', 'M', 'A', 'C', '8753', 'S', '1253', 'r', 'Z', '4205', '823', 'v', 'r', '3257', 'B', '3441', '23', '6979', 'V', 'X', '2923', '1221', '6345']

1575, 24, 2, 14, 13, 1, 3, 8753, 19, 1253, 18, 26, 4205, 823, 22, 18, 3257, 2, 3441, 23, 6979, 22, 24, 2923, 1221, 6345