Problem A
Elliptic Curve Addition
Languages
en
is
Let $p$ be a prime and $a,b\in \mathbb {F}_p$ such that $4a^3 + 27b^2 \not\equiv 0 \pmod{p}$. Let $P=(x_1,y_1)$ and $Q=(x_2,y_2)$ be two points on the elliptic curve $E : y^2 = x^3+ax+b$. Calcuate $P \oplus Q$ given $p, a, b, x_1, y_1, x_2$ and $y_2$.
Input
First line consists of three integers, $0 < p < 2^{31}-1$, $0 \leq a < p$ and $0 \leq b < p$, where $p$ is a prime. Second line consist of two integers $-1 \leq x_1, y_1 < 2^{31}-1$ where $(x_1,y_1)=(-1,-1)$ is the point at infinity. Third line consists of two integers $-1 \leq x_2, y_2 < 2^{31}-1$ where $(x_2,y_2)=(-1,-1)$ is the point at infinity.
Output
Output one line with the coordinates of $P \oplus Q$ seperated by space. Both coordinates should be $-1$ if the result is the point at infinity.
Sample Input 1 | Sample Output 1 |
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13 0 1 5 3 2 3 |
6 10 |
Sample Input 2 | Sample Output 2 |
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17 1 0 11 13 11 4 |
-1 -1 |