from collections import deque


def main():
    N = int(input())
    consumers = []
    for _ in range(N):
        _, *p = map(int, input().split())
        consumers.append(deque(p))
    new_waited = []

    while consumers:
        for consumer in consumers:
            try:
                new_waited.append(consumer.popleft())
            except IndexError:
                pass
        consumers = list(filter(lambda elm: len(elm) > 0, consumers))

    print(*new_waited)


if __name__ == "__main__":
    main()