from collections import deque
n = int(input())
q = deque()
for _ in range(n):
    p, *a = map(int,input().split())
    q.append(a[::-1])
ans = []
while q:
    v = q.popleft()
    if v:
        ans.append(v.pop())
        if v: q.append(v)
print(*ans)