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, 3, ['2047', 'R', '6885', '1243', 'Z']
[EX A]: 5886

[EX Q]: 3, 6, ['643', 'X', 'F', '7453', '8495', '7943']
[EX A]: 349759483547F

[EX Q]: 1, 7, ['1775', 'L', '6659', 'n', '6983', '6837', '9079', '1815', '8067', 'v', 'B']
[EX A]:
970973863896n9566L5771