A mapping company is testing a new signal simulation system. They have placed $$$N$$$ signal towers at different positions on a flat map. Each tower is located at coordinates $$$(x_i, y_i)$$$, where $$$1 \le x_i, y_i \le 2 \cdot 10^5$$$, all $$$y_i$$$ values are distinct and all $$$x_i$$$ values are distinct as well, additionally, there are no three colinear points.
To analyze signal interference, the company draws a virtual line between every pair of towers. These lines are extended downward, and the engineers are interested in how these lines affect positions on a distant horizontal scan line at $$$y = -10^{18}$$$.
They define a function $$$f(x)$$$ for real numbers $$$x$$$, which represents interference at horizontal position $$$x$$$ on the scan line. Initially, $$$f(x) = 0$$$ for all $$$x$$$.
Then, for every pair of towers $$$i \lt j$$$, the following process is applied:
Here, $$$\oplus$$$ denotes the bitwise XOR operation.
After processing all pairs, the function $$$f(x)$$$ becomes piecewise constant: the real line is divided into a number of intervals where $$$f(x)$$$ has the same value. We define a Trujo as any such interval where $$$f(x) = 0$$$.
Your task is to count how many Trujos appear on the real number line.
The first line contains three integers $$$N$$$, $$$a$$$, and $$$b$$$ $$$(2 \le N \le 2 \cdot 10^5,\ 0 \le a,b \le 10^9)$$$.
The next $$$N$$$ lines each contain two integers $$$x_i$$$, $$$y_i$$$ $$$(1 \le x_i, y_i \le 4 \cdot 10^5)$$$. All $$$y_i$$$ values are distinct and all $$$x_i$$$ values are distinct, additionally, there are no three colinear points.
Print one integer — the number of Trujos, i.e., the number of intervals on the real number line where $$$f(x) = 0$$$.
4 7 121 77 53 104 9
4