Xia Yu drew a cross on the paper, and drew a small circle in the middle of the cross - the small circle was himself. When he is at a loss, he will make this choice, continue or give up, change the goal or work hard to move forward. In most cases, it works, but today, he can't make any move. "She is really good-looking," Xia Yu thought as she tore off the paper and put it into the wastebasket beside the table. In the years that followed, the lush green trees on the campus in his memory were blurred, and the flowing water dried up. However, the pale yellow light of that night and the word "regret" under the crosshairs on the grid paper became increasingly clear, and occasionally appeared in his sighs.