open_addressing

M = 200003
Z = 100003
COUNT = 0


class Record:
    def __init__(self, uid=-1, v=-1):
        self.uid = uid
        self.v = v


def seek_pos(uid, table, skip=True):
    bucket = uid % M
    while table[bucket] and table[bucket].uid != uid and \
            (table[bucket].uid != -1 or skip):
        bucket = (bucket + Z) % M
    return bucket


def put(uid, v, table):
    bucket = seek_pos(uid, table, skip=False)
    global COUNT
    if table[bucket] and COUNT:
        COUNT -= 1
    table[bucket] = Record(uid, v)


def get(uid, table):
    bucket = seek_pos(uid, table)
    if not table[bucket]:
        return False
    return table[bucket].v


def delete(uid, table):
    bucket = seek_pos(uid, table)
    if not table[bucket]:
        return False
    table[bucket].uid = -1
    global COUNT
    COUNT += 1
    return table[bucket].v


def reset(table):
    hash_table = [None] * M
    for record in table:
        if record and record.uid != -1:
            put(record.uid, record.v, hash_table)
    return hash_table


def process_commands(n):
    global COUNT
    hash_table = [None] * M
    for _ in range(n):
        args = (input() + ' 0').split()[:3]
        cmd = args[0]
        uid = int(args[1])
        v = int(args[2])
        res = {'put': lambda uid, v: put(uid, v, hash_table),
               'get': lambda uid, _: get(uid, hash_table),
               'delete': lambda k, _: delete(uid, hash_table)}[cmd](uid, v)
        [0 if res is None else print(None) if res is False else print(res)]
        if COUNT > M / 10:
            hash_table = reset(hash_table)


n = int(input())
process_commands(n)