N = int(input())
PA = [list(map(int, input().split())) for _ in range(N)]
P = 0
for i in range(N):
    P = max(P, PA[i][0])
p = 0
ans = []
for p in range(1, P+1):
    for i in range(N):
        if p<=PA[i][0]:
            ans.append(PA[i][p])
print(*ans)