# coding: utf-8


def main():
    N = int(input())
    seats = [[] for _ in range(20)]
    for _ in range(N):
        seats, output = _next(seats)
        if output:
            print(output)


def _next(seats):
    funcs = { '0': sit, '1': serve, '2': leave }
    inputs = input().split(' ')
    return funcs[inputs[0]](seats, *inputs[1:])


def serve(seats, sushi):
    for i, s in enumerate(seats):
        if _index(s, sushi) != -1:
            seats[i] = remove(s, _index(s, sushi))
            return seats, i+1
    return seats, -1


def remove(l, i):
    return list(map(lambda t: t[1], filter(lambda t: t[0] != i, enumerate(l))))
    
    
def _index(l, e):
    if e in l:
        return l.index(e)
    else:
        return -1
    

def sit(seats, i, *info):
    i = int(i)
    seats[i-1] = list(info[1:])
    return seats, None


def leave(seats, i):
    i = int(i)
    seats[i-1] = []
    return seats, None


if __name__ == '__main__':
    main()