19137번 - Simple Polygon 스페셜 저지다국어

문제

Although bobo is truly smart, he just like you to find a simple polygon for him. The polygon you are going to find should satisfy the following conditions.

1. The polygon is simple. That is to say, any two non-adjacent edges won't intersect or touch and any two adjacent edges have exactly one common point.
2. Edges of the polygon are parallel to either $x$-axis or $y$-axis.
3. The perimeter of the polygon equals to $l,ドル while the area equals to $s$.

입력

First line of the input contains two integers $l$ and $s$ (4ドル \leq l \leq 10^9, 1 \leq s \leq 10^9$).

출력

The first line contains an integer $n,ドル which denotes the number of vertices of the polygon you have found (4ドル \leq n \leq 1000$).

Each of the following $n$ lines contains 2ドル$ integers $x_i, y_i,ドル which denote the coordinates of points (in clockwise or counter-clockwise order) (0ドル \leq x_i, y_i \leq 10^9$).

Any appropriate solution will get accepted.

If no such polygon can be found, simply print "-1".

제한

힌트