In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting string. 'i' and 'j' will be non-negative, and will always have a value less than the length of A. 'i' will always be less than 'j'. Perform the operations in order, i.e., do not reverse first and then concatenate.
11, 21, ['U', 'L', '2875', '1507', '5113', '3399', 'q', '867', '9847', 'w', '9065', 'X', '6657', 'w', 'd', 'k', 'C', 'B', '209', '9933', '4049']