from collections import deque
n = int(input())
customers = []
lmax = 0
for i in range(n):
    line = input().split()
    if int(line[0]) > lmax:
        lmax = int(line[0])
    customers.append(line[1:])
for x in customers:
    if int(x[0]) > lmax:
        lmax = int(x[0])

dic = {}
for x in range(n):
    for c in range(len(customers[x])):
        dic[(x,c)] = customers[x][c]
re = ""
for x in range(lmax):
    for y in range(n):
        if dic.get((x,y)):
            re += dic.get((x,y))
            re += " "
print(re[:-1])