Chocolate and knight game

Coco likes chess. One day Coco thought the movement of a knight is too simple, so he invented a fairy piece called a K-knight. A knight can move two squares in one direction (horizontal or vertical) and then one square in a perpendicular direction. A K-knight can move $X$ squares in one direction and then $Y$ squares in a perpendicular direction.

The knight game is a one-player game played on an infinite grid of chocolate. Initially, a knight is placed at the origin $(0, 0)$. Every turn, the player moves the knight according to its movement rule, and eats the previous chocolate cell the knight was on. The player cannot move the knight to a cell with no chocolate. The game ends when the player cannot move the knight anymore.

Hanbyeol just lost a game of Rock-Paper-Scissors with Coco, so she has to play a knight game on a 99% Cacao chocolate board. If the knight is replaced with a K-knight in this game, find out how to minimize the number of moves until the game ends.

The first line of input contains the integers $X$ and $Y$ separated by space, which define the movement rules of a K-knight. ($0 \le X, Y \le 10^6$)

Output the number of moves $K$ on the first line. Then, over the next $K$ lines, output the $x$ and $y$ coordinates of the K-knight after each of the $K$ moves.