There are two different parallel lines $$L_1$$ and $$L_2$$ and there are $$N$$ segments connecting them. Each segment connects two points $$(x_i, y_i)$$ and $$(x'_i, y'_i)$$ from these lines. You can assume that all the points $$(x_i, y_i)$$ belong to $$L_1$$ and all the points $$(x'_i, y'_i)$$ belong to $$L_2$$.
Your task is to find a subset of these segments such that there won’t be any two segments crossing each other. It is guaranteed that all the given points have distinct coordinates.

Input Format
The first line contains an integer $$N$$, the number of segments $$(1 \leq N \leq 10^5)$$. 
Each of the next $$N$$ lines contain \(4\) space-separated integers $$x_i, y_i, x'_i, y'_i$$ - each describing the endpoints of a segment $$(-10^9 \leq x_i, y_i, x'_i, y'_i \leq 10^9)$$. 

Output Format
Print the maximum number of segments such that there won’t be any two of them crossing each other.