NSTEPS - Number Steps

如下图，将自然数0，1，2，…写在平面直角坐标系内，问在点（x，y）处是否写了一个数，如果有，输出这个数，否则输出“No Number”。  例如1写在（1，1），2写在（2，0），3写在（3，1）。 输入格式：第1行一个数N，有N组测试数据。 接下来N行，每行一组测试数据，2个数x，y，表示点（x，y）。（0<=x，y<=10000） 输出格式：N行，每行一组测试数据，1个数或“No Number”。 感谢@qq1010903229 提供的翻译

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...10000.

The first line of the input is N, the number of test cases for this problem. In each of the N following lines, 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.

3
4 2
6 6
3 4

6
12
No Number