I am glad to invite you to participate in Codeforces Beta Round #57 (Div. 2).
Today's Contest was prepared by Amir Goharshady and Me.
We are thankful to Mike Mirzayanov , Artem Rakhov , Gerald Agapov , Mohammad Javad Naderi , Saeed Ilchi and Maria Belova.
Today's contest is dedicated to Khaje Nasir Tusi (Great Persian mathematician) since today is the national day of engineering in Iran.
You can download PDF version of statement from this link when the contest starts:
Have a good contest.
Alireza Farhadi and Amir Goharshady