N = int(input())
L = [None]*N
mp = 0
for i in range(N):
    p, *L[i] = map(int, input().split())
    mp = max(mp, p)
ans = []
for i in range(mp):
    for j in range(N):
        if i < len(L[j]):
            ans.append(L[j][i])
print(*ans)