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: 5, 7, ['x', 'B', '6829', 'c', 'K', '3021', 'U', '9989', 's', 'c', '345', '4423', 'j', 'S', 'E', 'r', 't', 'F', '1739', 'y']

K3021U