import collections


def solve(num_rows, customer_rows):
    customer_queues = [collections.deque(row) for row in customer_rows]
    res_row = []
    while any(customer_queues):
        for i in range(num_rows):
            if customer_queues[i]:
                res_row.append(customer_queues[i].popleft())
    return res_row


def main():
    n = int(input())
    customer_rows = []
    for _ in range(n):
        args = [int(z) for z in input().split()]
        row = args[1:]
        customer_rows.append(row)
    res = solve(n, customer_rows)
    print(*res)


if __name__ == "__main__":
    main()