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: 20, 21, ['u', 'd', 'Q', '9049', '3975', 'f', 'N', 'j', '7723', '865', '5459', 'X', 'n', '2037', 'Y', '2611', 'u', 'Z', '5045', '6635', 'E']

6635E