def get_lower_resolution(elevation_map: List[List[int]]) -> List[List[int]]:

"""Return a new elevation map, which is constructed from the values

of elevation_map by decreasing the number of elevation points

within it.

Precondition: elevation_map is a valid elevation map.

>>> get_lower_resolution(

...[[1, 6, 5, 6],

...[2, 5, 6, 8],

...[7, 2, 8, 1],

...[4, 4, 7, 3]])

[[3, 6], [4, 4]]

>>> get_lower_resolution(

...[[7, 9, 1],

...[4, 2, 1],

...[3, 2, 3]])

[[5, 1], [2, 3]]

"""