N = int(input())

A = []
max_p = 0
for i in range(N):
    x = list(map(int, input().split()))
    A.append(x)
    if x[0] > max_p:
        max_p = x[0]
    
for i in range(max_p):
    for j in range(N):
        if len(A[j]) == 1:
            pass
        else:
            print(A[j][1], end=' ')
            del A[j][1]