An integer interval [a, b] (for integers a < b) is a set of all consecutive integers from a to b, including a and b. Find the minimum size of a set S such that for every integer interval A in intervals, the intersection of S with A has a size of at least two. Example 1: Input: intervals = [[1,3],[1,4],[2,5],[3,5]] Output: 3 Explanation: Consider the set S = {2, 3, 4}. For each interval, there are at least 2 elements from S in the interval. Also, there isn't a smaller size set that fulfills the above condition. Thus, we output the size of this set, which is 3. Example 2: Input: intervals = [[1,2],[2,3],[2,4],[4,5]] Output: 5 Explanation: An example of a minimum sized set is {1, 2, 3, 4, 5}. Constraints: 1 <= intervals.length <= 3000 intervals[i].length == 2 0 <= ai < bi <= 108