def closest_pair(coordinates):
    if len(coordinates) <= 2:
        return coordinates

    coordinates.sort(key=lambda x: x[1])
    mid = len(coordinates) // 2
    left = closest_pair(coordinates[:mid])
    right = closest_pair(coordinates[mid:])
    return merge(left, right)


def merge(a1, a2):
    min_dist = float("inf")
    min_dist_points = []

    for i in range(len(a1) - 1):
        x1, y1 = a1[i]
        x2, y2 = a1[i + 1]
        dist = calc_dist(x1, y1, x2, y2)
        if dist < min_dist:
            min_dist = dist
            min_dist_points = [(x1, y1), (x2, y2)]

    for i in range(len(a2) - 1):
        x1, y1 = a2[i]
        x2, y2 = a2[i + 1]
        dist = calc_dist(x1, y1, x2, y2)
        if dist < min_dist:
            min_dist = dist
            min_dist_points = [(x1, y1), (x2, y2)]

    x1, y1 = a1[-1]
    x2, y2 = a2[0]
    dist = calc_dist(x1, y1, x2, y2)
    if dist < min_dist:
        min_dist = dist
        min_dist_points = [(x1, y1), (x2, y2)]

    return min_dist_points


def calc_dist(x1, y1, x2, y2):
    return ((y2 - y1) ** 2 + (x2 - x1) ** 2) ** (1 / 2)


points = [(1, 1), (-1, 5), (2, 5), (6, 3), (-10, 5)]
print(closest_pair(points))