TASK 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.
PROBLEM: ['E', '5573', '7669', '6989', 'a', '731', '7747', 'U', '6599', '549', 'd', '6193', 'y', '4005', '7097', 'C', '5707', '3791', '9671']

SOLUTION: 5, 5573, 7669, 6989, 1, 731, 7747, 21, 6599, 549, 4, 6193, 25, 4005, 7097, 3, 5707, 3791, 9671

PROBLEM: ['d', '3', 'Y', 't', 'B', '8295']

SOLUTION: 4, 3, 25, 20, 2, 8295

PROBLEM: ['839', 'D', '8587', '2657', 'K', 'C']

SOLUTION:
839, 4, 8587, 2657, 11, 3