25787번 - Square Fishing Net 다국어

문제

With so many activities/events being virtual these days, we are going on a virtual fishing trip!

Given the (x,y) coordinates of n points (each point represents a fish) and a square (representing a fishing net), what is the maximum fish you can catch with one try? You can place the square net anywhere but its sides must be parallel to X-axis and Y-axis. A fish is caught if it is inside or on the boundary of the net.

입력

The first input line contains two integers: s (1 ≤ s ≤ 100), indicating the length of one side of the fishing net and n (1 ≤ n ≤ 100), indicating the number of fish. Each of the next n input lines contains two integers (each between 1 and 100, inclusive) indicating the (x,y) coordinates of one fish. Assume that no two fish are at the same location.

출력

Print the maximum number of fish you can catch.

제한

힌트