Definition: 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 concatenate all elements of A from the ith element to the jth element, and print 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.
Input: 7, 21, ['R', '8315', 'l', '4177', 'Y', 'V', 'n', 'G', 'g', 'a', 'g', 'u', 'Q', '4087', '8439', '5393', 't', 'f', '4715', '8115', 'a', 'U', 'R', 'e', 'P', 'A', 'Z', '9089']

nGgaguQ408784395393tf47158115a