s.pop() s.pop() s.push(21) print(s) s2 = Stack(17) s2.push(21) print(s == s2) s.push(12) print(s, s.top()) print(s.search(44), s.search(21)) q = Queue(44) q.enqueue(39) q.enqueue(31) q.enqueue(42) print(q) print(q.size(), q.back(), q.front()) q.dequeue() q2 = Queue() q2.enqueue(56) print(q != q2) q2.enqueue(67) q2.print_queue()