from functools import cmp_to_key
class Solution:
    def removeCoveredIntervals(self, intervals: List[List[int]]) -> int:
        def func(x,y):
            if x[0]<y[0]:
                return -1
            elif x[0]==y[0]:
                if x[1]>y[1]:
                    return -1
                elif x[1]==y[1]:
                    return 0
                else:
                    return 1
            else:
                return 1
        l=sorted(intervals,key=cmp_to_key(func))
        i=0
        while i<len(l)-1:
            if l[i][1]>=l[i+1][1]:
                del l[i+1]
            else:
                i+=1
        return len(l)