Thank you for explaining. (I am NOT Chinese.) I would like to confirm original problem's condition. If the condition is "x is integer", the solution is x=256. But, if the condition is "x is real number", there are other solutions. One is between 1 and 2, the other is between -1 and 0. (I don't know Chinese, so, I cannot get the information about that from this video. Therefore, I am asking about original problem's condition.)