Find Final Cart

The cart starts with the items in the given order. A positive query x appends x to the end; a negative query −x removes the first occurrence of x currently in the cart. Output the final cart. This site's test cases guarantee that the item exists at every removal, and the behavior of removing a missing item, which the source does not specify, is left undefined.

输入格式

The first line contains n q (both 1..200000), the second line contains n initial items (1..10⁹), and the third line contains q non-zero queries (−10⁹..10⁹). The item of every removal query is currently present.

输出格式

First output the final number of items, then the items in order; if the cart is empty, output only 0.

样例 1

输入：

5 5
1 2 1 2 1
-1 -1 3 4 -3

输出：

4 2 2 1 4

样例 2

输入：

1 1
1
-1

输出：

0

样例 3

输入：

3 2
2 1 2
-2 2

输出：

3 1 2 2

样例说明

Example 1: after removing the first two occurrences of 1, [2,2,1] remains; append 3 and 4, then remove 3, ending with [2,2,1,4], so output the count 4 first. Example 2: after removing the only item, output 0. Example 3: remove the first 2, then append 2, giving [1,2,2], so output 3 1 2 2.