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: 12, 20, ['U', '7505', 'I', 'W', '5137', 'G', 'H', 'b', '5787', 'j', '8767', '6805', '4719', 'G', '19', 'i', 'y', '2945', 'I', 'p', '4101']

68054719G19iy2945Ip