If such an array does not exist, then output ``$-1$''.

Otherwise, in the first line, output the number $n$ ($1 \le n \le 1000$)~--- the minimal size of the array.

In the second line, output the numbers $a_1,a_2,\dots,a_n$ ($1 \le a_i \le d$), which satisfy the condition.

If there are multiple correct answers, any of them are allowed.

It can be shown that the length of the optimal array always satisfies the constraint.