def main():
    N = int(input())
    P = []
    A = []
    for i in range(N):
        B, *C = map(int, input().split())
        P.append(B)
        A.append(C)
    maxP = max(P)
    for i in range(N):
        A[i] += [0] * maxP
    ans = []
    for j in range(maxP):
        for i in range(N):
            if A[i][j] == 0:
                continue
            ans.append(A[i][j])
    print(*ans)


if __name__ == "__main__":
    main()