There are N empty boxes arranged in a row from left to right. The integer i is written on the i-th box from the left (1 \leq i \leq N).  For each of these boxes, Snuke can choose either to put a ball in it or to put nothing in it.  We say a set of choices to put a ball or not in the boxes is good when the following condition is satisfied:    * For every integer i between 1 and N (inclusive), the total number of balls contained in the boxes with multiples of i written on them is congruent to a_i modulo 2.  Does there exist a good set of choices? If the answer is yes, find one good set of choices.
print(-1)
n = int(input())
A = [0] + [int(a) for a in input().split()]
B = [0]*(n+1)
B[-1] = A[-1]
for i in range(n-1,0,-1):
    a = A[i]
    for j in range(i,n+1,i):
        a += B[j]
    B[i] = a%2
s = sum(B)
print(s)
if s != 0:
    print(*[idx for idx,b in enumerate(B) if b==1])