Find all pairs $(x, y)$ of real numbers satisfying the equations \begin{align*} x^2+y&=xy^2 \\ 2x^2y+y^2&=x+y+3xy. \end{align*}

A and B plays a game on a pyramid whose base is a $2016$-gon. In each turn, a player colors a side (which was not colored before) of the pyramid using one of the $k$ colors such that none of the sides with a common vertex have the same color. If A starts the game, find the minimal value of $k$ for which $B$ can guarantee that all sides are colored.

Let $n$ be a positive integer, $p$ and $q$ be prime numbers such that \[ pq \mid n^p+2 \quad \text{and} \quad n+2 \mid n^p+q^p. \]Prove that there exists a positive integer $m$ satisfying $q \mid 4^m \cdot n +2$.

In a trapezoid $ABCD$ with $AB<CD$ and $AB \parallel CD$, the diagonals intersect each other at $E$. Let $F$ be the midpoint of the arc $BC$ (not containing the point $E$) of the circumcircle of the triangle $EBC$. The lines $EF$ and $BC$ intersect at $G$. The circumcircle of the triangle $BFD$ intersects the ray $[DA$ at $H$ such that $A \in [HD]$. The circumcircle of the triangle $AHB$ intersects the lines $AC$ and $BD$ at $M$ and $N$, respectively. $BM$ intersects $GH$ at $P$, $GN$ intersects $AC$ at $Q$. Prove that the points $P, Q, D$ are collinear.

In an acute triangle $ABC$, the feet of the perpendiculars from $A$ and $C$ to the opposite sides are $D$ and $E$, respectively. The line passing through $E$ and parallel to $BC$ intersects $AC$ at $F$, the line passing through $D$ and parallel to $AB$ intersects $AC$ at $G$. The feet of the perpendiculars from $F$ to $DG$ and $GE$ are $K$ and $L$, respectively. $KL$ intersects $ED$ at $M$. Prove that $FM \perp ED$.

Prove that \[ (x^4+y)(y^4+z)(z^4+x) \geq (x+y^2)(y+z^2)(z+x^2) \]for all positive real numbers $x, y, z$ satisfying $xyz \geq 1$.

Find all pairs $(p, q)$ of prime numbers satisfying \[ p^3+7q=q^9+5p^2+18p. \]

Let $G$ be a simple connected graph with $2016$ vertices and $k$ edges. We want to choose a set of vertices where there is no edge between them and delete all these chosen vertices (we delete both the vertices and all edges of these vertices) such that the remaining graph becomes unconnected. If we can do this task no matter how these $k$ edges are arranged (by making the graph connected), find the maximal value of $k$.