Go Back in Time and Save Your Deskmate

My deskmate had a heart disease and was slapped by the teacher from behind. I inadvertently traveled back to two years before my deskmate died. I thought of a way to save my deskmate. The system helped me become a top student. After graduation, I successfully developed a medicine that is effective against heart disease through the resources of the system and successfully cured my deskmate's disease. The following is to increase the self-proclaimed "don't worry" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.