Stark Industry is planning to organize Stark Expo, for which various departments have to organize meetings to check their preparations. Since Stark Tower has limited rooms available for the meeting, Tony decided to allot a room to each meeting so that all the meetings are organized in the least possible conference rooms, and a the moment, only one meeting will happen in one room. So, he asked JARVIS to allot each meeting a room and tell the minimum number of conference rooms to be reserved. But, since JARVIS was busy rendering another Iron Man suit model, he asked you to help. You are given an array of integers ARR of size N x 2, representing the start and end time for N meetings. Your task is to find the minimum number of rooms required to organize all the meetings.