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: ['5851', 'z', 'S', 'V', '1297', '8599', '7907', 'v', 'h', 'E', '917', 'g', 'z', 'w', 'u', '6659']

5851, 26, 19, 22, 1297, 8599, 7907, 22, 8, 5, 917, 7, 26, 23, 21, 6659