n, x, y = map(int, input().split())
if x == y:
    print(0)
    exit()
if y % 2 == 0:
    print(-1)
    exit()
ans = []
pre = n
for i in range(n)[::-1]:
    if y >> i & 1:
        ans.append(pre - i)
        pre = i
print(len(ans))
print(*ans)