Seo Yeon is a normal girl.She likes to spend her time by reading novels.If she have time,she will read novels.Even though,she have been reading the novels for the 6363468462839th times.BUT ! SHE's NOT GOOD AT MATH.She always get F in exam.She have tried her best.But,it's doesn't work at all.Sigh was her reaction when she looked the "F" letter written on the