"hiho" is a weekly series of contest we developed to help programmers improve their skills following some architecture. In the several following weeks we will learn number theory algorithms with Little Hi and Little Ho. Number theory is a very special academic sub-domain in mathmatics and is said to be the "crown of mathmatics". In computer science, number theory is widely used in fields such as cryptography. This week we will learn how to solve the Josephus problem efficiently.