import sys input = sys.stdin.read data = input().split() # print(data) # ['7', 'push', '1', 'push', '2', 'size', 'query', 'pop', 'pop', 'query'] n = int(data[0]) stack = [] index = 1 output_lines = [] for _ in range(n): op = data[index]; index += 1 if op == 'push': x = data[index]; index += 1 stack....