2. {40 points} Dave works in human resources. He has a list of times when employees take their break. Break time is represented as an interval [i,j] indicating that it starts at time i and ends at time j. He notices that employees who are close friends with each other have overlapping breaks. For example, if employee a and b are close friends and if a takes his break in the interval [k,l] and b takes her break in the interval (m, n) such that k