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]: 3, 4, ['6865', 'A', 's', 'o', '1989', 'i', '613', 'S', 's']
[EX A]: os

[EX Q]: 3, 4, ['E', 'k', '4697', 'f', 'J', 's', '1265', '4673', 'D', '3345', 'n', '5593', '2249', '5951']
[EX A]: f7964

[EX Q]: 3, 12, ['c', 'w', 'I', '1429', '4183', '3545', '677', '2209', '9813', 'J', '6843', '4175', '4347', '5537', 'B', 'O', 'O']
[EX A]:
57143486J31899022776545338149241I