In this task, you are given inputs i, j, and A, where i and j are integers and A is a list. You need to find all elements of A from the ith element to the jth element, reverse the order in which they occur, and then concatenate them to output the resultant 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 concatenate the elements and then reverse the string.
7, 19, ['p', 'x', '6755', 'G', 'R', '5729', '6249', 'C', 'X', 'H', 'L', 'i', '7837', '4429', 'n', '6359', '8811', '27', 'f']