@admin As the problem INTROVERTS in the last contest was straight forward C++ STL based using set and then applying lower_bound() and upper_bound() functions on it. In python, there is no inbuilt data structure which keeps elements sorted during insertion due to which the last problem got complex for me. However, there is a module named “sortedcontainers” in Python on which we can use the bisect module functions to get the same job done as in C++. But sortedcontainers in not supported on CodeChef. So, I would like to request you to add it in CodeChef.