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.

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


[Q]: 6, 7, ['2289', '1015', 'T', 'e', '4499', 'J', 'B', '5107', 'x', '3103', 'Q', 'Z', 'H']
[A]: BJ


[Q]: 18, 21, ['c', 'C', 'c', '5173', 'Q', 'D', 'f', 'X', '7707', '4085', '1057', '3347', 'X', '6749', 'd', '3395', 'i', 'T', '4943', 'D', 'w', 's', 'c', '7635', '2721', 'u', '9721', '3949']
[A]:
wD3494T