ex_test 8: $f(x,y) = xy$ https://uoj.ac/hack/14271

ex_test 9: $f(x,y) = \min(x,y)$ https://uoj.ac/hack/14274

ex_test 10: $f(x,y) = 4\times 10^{11}(x+y)+xy$ https://uoj.ac/hack/14280

暂时叉不掉的：https://uoj.ac/submission/705202

欢迎大家在评论区提交 hack.