A group of Castellers has decided to make a human tower to celebrate Catalonia's national holiday. For practical and aesthetic reasons, each person in the tower must be shorter and lighter than the person below him or her.
Given the heights and weights of each person in the group, write a method to compute the largest possible number of people in such a tower.
Input (height, weight): (65, 100) (70, 150) (56, 90) (75, 190) (60, 95) (68, 110)
Output: The longest tower is length 6 and includes from top to bottom: (56, 90) (60,95) (65,100) (68,110) (70,150) (75,190)