**"Between Longitude and Latitude"**
"She was the unsolvable coordinate in my youth, and the answer I finally dared to write down when I grew up."
Seventeen-year-old Chen Shaohang has a secret - on the last page of her geography notebook, the silhouette of Teacher Song from the mathematics group is filled with pencil.
At that time, Song Jingning was a young teacher who came to practice. When he stood on the podium and explained trigonometric functions, he always liked to tap the blackboard with his fingertips. Chen Shaohang would deliberately write a wrong question when handing in her homework, just to get her red pen annotation of "listen carefully in class." Until that rainy day, she bumped into Song Jingning in an empty classroom tremblingly stroking her forgotten notebook——
"What are you looking at, teacher?"
"I'm looking at... A problem that can never be solved."
Five years later, Chen Shaohang, a newly hired geography teacher, opened the door of the teaching and research office and was caught off guard by a pair of familiar eyes. Song Jingning, who has become a key teacher, still has the geography notes that were stained by the rain on the lesson plan in hand.
"This time, let me be your coordinate system."
Intention: In the intersection of longitude, latitude and coordinates, we finally found the only solution to love.