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:3Explanation: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:5Explanation:An example of a minimum sized set is {1, 2, 3, 4, 5}.

**Constraints:**

`1 <= intervals.length <= 3000`

`intervals[i].length == 2`

`0 <= a`

_{i}< b_{i}<= 10^{8}

class Solution:
def intersectionSizeTwo(self, intervals: List[List[int]]) -> int: