class Solution:
    def insert(self, intervals: List[List[int]], newInterval: List[int]) -> List[List[int]]:
        intervals.append(newInterval)
        intervals = sorted(intervals, key = lambda x: x[0])
       
        i = 0
        while i < len(intervals) - 1:
            if intervals[i][1] >= intervals[i+1][0]:
                intervals[i][1] = max(intervals[i][1], intervals[i+1][1])
                del intervals[i+1]
            else:
                i += 1
        return intervals
        