N = int(input())
A = [[0] * (100) for _ in range(N)]
for i in range(N):
    p, *a = map(int, input().split())
    if p != 0:
        for j in range(p):
            A[i][j] = a[j]

ans = []
for j in range(100):
    for i in range(N):
        if A[i][j] != 0:
            ans.append(A[i][j])
print(*ans)