Robot - MarisaOJ: Marisa Online Judge

You have a robot located at point

$(0, 0)$ on a 2D plane. The robot can run

$n$ command. If the robot are now at

$(x, y)$ , and you execute the

$i^{th}$ command, your robot will move to

$(x + x_i, y + y_i)$ . Each command can only be executed only once. Count the number of way to reach point

$(a, b)$ . ### Input - The first line contains an integer

$n$ . - The second line contains 2 integers

$a, b$ . - The next

$n$ lines, each line contains 2 integers

$x_i, y_i$ . ### Output - Print the number of ways to reach point

$(a, b)$ . ### Constraints -

$1 \le n \le 40$ . -

$-10^9 \le x_i, y_i, a, b \le 10^9$ . ### Example Input:

$2 1 1 0 1 1 0$

Output:

$1$

Topic

Meet in the middle

Rating

900

Solution (0)

Solution