from sys import stdin

def main():
    input = lambda: stdin.readline()[:-1]
    N = int(input())
    A = [[0] * 100 for _ in [0] * N]
    for i in range(N):
        s = list(map(int, input().split()))
        A[i][:s[0]] = s[1:]

    ans = []
    for i in range(100):
        for j in range(N):
            if A[j][i]:
                ans.append(A[j][i])
    print(*ans)

main()