// luogu-judger-enable-o2
include <cstdio>
//include <iostream>
include <cstring>
include <algorithm>
include <cmath>
define R(a,b,c) for(regist ......
原文链接
There are many trees forming a m * n grid, the grid starts from (1,1). Farmer Sherlock is standing at (0,0) point. He wonders how many trees ......