query =[]
number_of_queries = int(input())
for q in range(number_of_queries):
    operation = input().split()
    if len(operation) == 2:
        query.append(operation[1])
    elif len(operation) == 1 and operation[0] != '3':
        query.remove(query[0])
    elif operation[0] == '3':
        print(query[0])