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.

[EX Q]: 1, 5, ['3155', '5437', '1383', 'L', 'a']
[EX A]: aL383173455513

[EX Q]: 3, 20, ['x', 'S', 's', 'a', '5077', 'D', '3979', 'I', '3129', 'R', '8517', 'r', 'l', 'K', 'N', '9701', '227', 'n', '9385', 'U']
[EX A]: U5839n7221079NKlr7158R9213I9793D7705as

[EX Q]: 2, 7, ['143', '3629', 't', '9099', 'v', '2167', 'D', '8803', '5973', '9605', '591', '5151', '9391', 'I', 'B', 'I', 'y', '5779', 'k']
[EX A]:
D7612v9909t9263