I don't know why many negative comments about this drama in the comment section(It's not like it never happened in our world ) made me hesitate to watch it but thankfully I gave it a shot for Actor Lee Do Hyun(18 again,youth of may) and Diretor Kim Sang Hyub(Extraordinary You,True beauty)in the end I'm Amazed!!. I have watched 311 Dramas so far never seen this type of approach for mathematicians in any dramas i watched ,also story line is bit different than other romance dramas. Are you bored watching regular romance dramas with the same buildup between lead roles??? Then this is definitely for you. First of all big kudos to "Lee Do Hyun" and "Im Soo Jung" for choosing this script, especially Lee Do Hyun after giving outstanding performance and a hit dramas like "18 again" and "youth of May". He decided this script which shows his braveness and gave phenomenon performance in this.Now he is in top 5 fav actor in my list after this drama.He's choosing different genres and story line which is impressive for a starter and his acting level is awesome.Everyone in this drama acted so well which is very positive to this drama and made viewers more interesting and held onto their seats. Big thanks to the screen writer Kim Ji Woon did a great job here after "Doctor John" .I dont want to be a spoiler so I'm not revealing much about the story but you wont regret watching it in the end......Give it a shot!!!!