from itertools import groupby import sys input_data = sys.stdin.read() lines = input_data.strip().split('\n') group_num = int(lines[0]) t = 0 while t < group_num: str_length = int(lines[2*t+1]) string = lines[2*t+2].strip() res = '' for i in range(len(string)-1,-1,-1): if string[i] != ' ': res += string[i] print(res) t += 1