PinkieRabbit,we love you
English version:
Practice more,noob
You can't see the answer, doesn't it mean you have low intelligence?
If you insist on rigorous proof, then you will never be able to come up with a conclusion, as others have already guessed the conclusion.
Chinese version:
菜就多练
你看不出道理不是正说明你悟性低?
非得要严谨证明,那你结论题永远做不出来,别人早就猜到了。