import collections
N = int(input())
ls = []
for i in range(N):
    a = list(map(int,input().split()))
    if len(a) == 1:
        ls.append(collections.deque())
    else:
        ls.append(collections.deque(a[1:]))
ans = []
while ls:
    ll = []
    for q in ls:
        if not q:
            continue
        ans.append(q.popleft())
        ll.append(q)
    ls = ll
print(*ans)