class Solution:
    def intervalIntersection(self, A: List[List[int]], B: List[List[int]]) -> List[List[int]]:
        res = []

        i = 0
        j = 0


        while(i < len(A) and j < len(B)):


            while(i < len(A) and A[i][1] < B[j][0]):
                i+=1

            if i == len(A):
                break

            while(j < len(B) and B[j][1] < A[i][0]):
                j+=1

            if j == len(B):
                break

            if A[i][1] < B[j][0] or A[i][0] > B[j][1]:
                continue


            interval = [0,0]
            interval[0] = max(A[i][0], B[j][0])
            interval[1] = min(A[i][1], B[j][1])

            res.append(interval)

            if A[i][1] < B[j][1]:
                i+=1
            else:
                j+=1

        return res