c1 oa

def soln(points):
    # assuming no dup points
    dd = collections.defaultdict(set)
    for x, y in points:
        dd[x].add(y)
    ans = 0
    for x, y in points:
        for _x  in [x+1, x+2]:
            for _y in [y-2, y-1, y, y+1, y+2]:
                if _y in dd[_x]:
                       ans += 1
        for _x  in [x]: # it's reduced to a 1D problem
            for _y in [y+1, y+2]:
                if _y in dd[_x]:
                       ans += 1 
    return ans