from __future__ import annotations
from collections import deque
from collections.abc import Iterable, Iterator
from dataclasses import dataclass
from itertools import islice
from math import sqrt
from sys import argv
from typing import TypeVar, Generic, Union, Optional, cast

NumT = TypeVar('NumT', float, int)

@dataclass(frozen=True)
class Point2D(Generic[NumT]):
    x: NumT
    y: NumT

    def __str__(self) -> str:
        return f'({self.x}, {self.y})'

    def __add__(self, other: Point2D[NumT]) -> Union[Point2D[NumT], bool]:
        if isinstance(other, Point2D):
            return Point2D(self.x + other.x, self.y + other.y)
        return NotImplemented

    def __sub__(self, other: Point2D[NumT]) -> Union[Point2D[NumT], bool]:
        if isinstance(other, Point2D):
            return Point2D(self.x - other.x, self.y - other.y)
        return NotImplemented

    def __abs__(self) -> Point2D[NumT]:
        return Point2D(cast(NumT, abs(self.x)), cast(NumT, abs(self.y)))

def norm_1(p: Point2D[NumT]) -> NumT:
    return cast(NumT, abs(p.x) + abs(p.y))

def norm_2(p: Point2D) -> float:
    return sqrt(p.x ** 2 + p.y ** 2)

def norm_inf(p: Point2D[NumT]) -> NumT:
    return cast(NumT, max(abs(p.x), abs(p.y)))

def inbounds(p: Point2D[NumT], a: Point2D[NumT], _b: Optional[Point2D[NumT]] = None) -> bool:
    if isinstance(_b, Point2D):
        b = _b
    else:
        b = a
        a = cast(Point2D[NumT], Point2D(0, 0))
    return p.x >= a.x and p.y >= a.y and p.x < b.x and p.y < b.y

def adjacent(p: Point2D[int], diagonal: bool = True) -> Iterator[Point2D[int]]:
    for dx in range(-1, 2):
        for dy in range(-1, 2):
            if dx == 0 and dy == 0: continue
            if dx != 0 and dy != 0 and not adjacent: continue
            yield Point2D(p.x + dx, p.y + dy)

def adjacent_bounded(p: Point2D[int], bound: Point2D[int], diagonal: bool = True) \
        -> Iterator[Point2D[int]]:
    return filter(lambda p: inbounds(p, bound), adjacent(p, diagonal))

T = TypeVar('T')
def sliding_window(iterable: Iterable[T], n: int) -> Iterator[tuple[T, ...]]:
    # sliding_window('ABCDEFG', 4) -> ABCD BCDE CDEF DEFG
    it: Iterator[T] = iter(iterable)
    window: deque[T] = deque(islice(it, n), maxlen=n)
    if len(window) == n:
        yield tuple(window)
    for x in it:
        window.append(x)
        yield tuple(window)

def open_day(n: int):
    if len(argv) == 2:
        return open(argv[1])
    return open(f'{n}.in')