The problem is 1041F - Ray in the tube

These words are copied from the problem:

To do so, you have to choose two integer points *A* and *B* on the first and the second line respectively (coordinates can be negative): the point *A* is responsible for the position of the laser, and the point *B* — for the direction of the laser ray. The laser ray is a ray starting at *A* and directed at *B* which will reflect from the sides of the tube (it doesn't matter if there are any sensors at a reflection point or not). A sensor will only register the ray if the ray hits exactly at the position of the sensor.

I think *A* and *B* only have to be integers, but it doesn't say they cannot be a straight line.

*B* as the direction, it even can out of the tube.

And my submission got Wrong Answer on test 51. (Submission : 43024618)

After the Virtual Participation, I got the test of test 51, and found n = 12000 and m = 32000

So I think the answer should be 32000, instead of 24000 (Submission : 43065546)

Because I can use a single line with A(-2,y2) and B(-1,y2) to get 32000 points instead of 24000.

Hope any of the problem setter can answer me. Roms BledDest adedalic fcspartakm

"...integer points A and B on the first and the second line

respectively" Doesn't this line says, that A should be on the first and B on the second line?