each line, there is x, and y representing the coordinates (x, y) of a point.
Starting from point (0,0) on a plane, we have written all non-negative integers 0,1,2, ... as shown in the figure. For example, 1, 2, and 3 has been written at points (1,1), (2,0), and (3, 1) respectively and this pattern has continued.
You are to write a program that reads the coordinates of a point (x, y), and writes the number (if any) that has been written at that point. (x, y) coordinates in the input are in the range 0...5000.
each line, there is x, and y representing the coordinates (x, y) of a point.
For each point in the input, write the number written at that point or write No Number if there is none.
4 2
6
北京大学机试题