import sys, collections
sys.setrecursionlimit(10 ** 6)
stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().strip()
ntp = lambda: tuple(map(int, stdin.readline().split()))
mod = 10 * 9 + 7
inf = 2 << 60

n = ni()
A = [''] * n
P = []
Ans = []
for i in range(n):
    a = na()
    P.append(a[0])
    if a[0] != 0:
        A[i] = a[1:][::-1]

for _ in range(max(P)):
    for j in range(n):
        if A[j]:
            Ans.append(A[j].pop())

print(*Ans)