Remove All Zeros While Preserving Order

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem

Given $a_0,a_1,\ldots,a_{n-1}$, remove every zero while preserving the relative order of all nonzero elements.

Let

$$J=\{i\mid0\le i<n,\ a_i\ne0\}=\{j_0<\cdots<j_{m-1}\}.$$

The result has length $m=|J|$ and $b_k=a_{j_k}$ for $0\le k<m$. If all elements are zero, then $m=0$ and the result is empty.

Input

The first line contains $n$. The second line contains $n$ integers $a_i$.

Output

Print $m$ on the first line. If $m>0$, print $b_0,\ldots,b_{m-1}$ on the second line; otherwise the second line is empty.

Subtask

Subtask 1 (20 points): $1\le n\le 10$, $|a_i|\le 10^3$.

Subtask 2 (30 points): $1\le n\le 5000$, $|a_i|\le 10^6$.

Subtask 3 (50 points): $1\le n\le 2\cdot 10^5$, $|a_i|\le 10^9$.

Example

Input

8
0 5 0 -2 7 0 0 4

Output

4
5 -2 7 4

Explanation

The output follows directly from the mathematical definition above.