import math


def find_slope(x1, y1, x2, y2):
    """ Returns a slope of line formed by the points in the format (deltaX, deltaY).
    """
    dy, dx = y2 - y1, x2 - x1
    if dx < 0:  # keep minus sign(if any) with dy
        dx *= -1
        dy *= -1
    g = math.gcd(dy, dx)
    return (dy // g, dx // g)


def is_right_angle(s1, s2):
    """ Returns True if angle formed by 2 lines with slopes s1 and s2 is 90.
    """
    dy1, dx1 = s1
    dy2, dx2 = s2
    dy, dx = dy1 * dy2, dx1 * dx2
    if dy == 0 and dx == 0:
        return True
    g = math.gcd(dy, dx)
    dy //= g
    dx //= g
    return dy < 0 and abs(dy) == dx == 1


def isRectangle(points):
    s1 = find_slope(*points[0], *points[1])
    s2 = find_slope(*points[3], *points[2])
    s3 = find_slope(*points[0], *points[3])
    s4 = find_slope(*points[1], *points[2])
    # check that lines are parallel and one of the angles is 90
    if s1 != s2 or s3 != s4 or not is_right_angle(s1, s3):
        return False
    return True

double det(double x1,double y1, double x2,double y2) {
    return x1*y2 - x2*y1;
}
bool isRectangle(std::vector<std::vector<int>> points) {
    swap(points[1],points[3]);

    double A = points[0][1] - points[1][1];
    double B = points[1][0] - points[0][0];
    double C = det(points[0][0],points[0][1],points[1][0],points[1][1]);

    double A2 = points[1][1] - points[2][1];
    double B2 = points[2][0] - points[1][0];
    double C2 = det(points[1][0],points[1][1],points[2][0],points[2][1]);

    double A3 = points[2][1] - points[3][1];
    double B3 = points[3][0] - points[2][0];
    double C3 = det(points[2][0],points[2][1],points[3][0],points[3][1]);

    double A4 = points[3][1] - points[0][1];
    double B4 = points[0][0] - points[3][0];
    double C4 = det(points[3][0],points[3][1],points[0][0],points[0][1]);


    double angle = (points[0][0]-points[1][0])*(points[2][0]-points[1][0]) 
                 + (points[0][1]-points[1][1])*(points[2][1]-points[1][1]);
    if(angle != 0) return false;

    return det(A,B,A3,B3) == 0 && det(A2,B2,A4,B4) == 0;
}

double det(double x1,double y1, double x2,double y2) {
    return x1*y2 - x2*y1;
}
bool isRectangle(std::vector<std::vector<int>> points) {
    swap(points[1],points[3]);

    double A = points[0][1] - points[1][1];
    double B = points[1][0] - points[0][0];
    double C = det(points[0][0],points[0][1],points[1][0],points[1][1]);

    double A2 = points[1][1] - points[2][1];
    double B2 = points[2][0] - points[1][0];
    double C2 = det(points[1][0],points[1][1],points[2][0],points[2][1]);

    double A3 = points[2][1] - points[3][1];
    double B3 = points[3][0] - points[2][0];
    double C3 = det(points[2][0],points[2][1],points[3][0],points[3][1]);

    double A4 = points[3][1] - points[0][1];
    double B4 = points[0][0] - points[3][0];
    double C4 = det(points[3][0],points[3][1],points[0][0],points[0][1]);


    double angle = (points[0][0]-points[1][0])*(points[2][0]-points[1][0]) 
                 + (points[0][1]-points[1][1])*(points[2][1]-points[1][1]);
    if(angle != 0) return false;

    return det(A,B,A3,B3) == 0 && det(A2,B2,A4,B4) == 0;
}

double det(double x1,double y1, double x2,double y2) {
    return x1*y2 - x2*y1;
}
bool isRectangle(std::vector<std::vector<int>> points) {
    swap(points[1],points[3]);

    double A = points[0][1] - points[1][1];
    double B = points[1][0] - points[0][0];
    double C = det(points[0][0],points[0][1],points[1][0],points[1][1]);

    double A2 = points[1][1] - points[2][1];
    double B2 = points[2][0] - points[1][0];
    double C2 = det(points[1][0],points[1][1],points[2][0],points[2][1]);

    double A3 = points[2][1] - points[3][1];
    double B3 = points[3][0] - points[2][0];
    double C3 = det(points[2][0],points[2][1],points[3][0],points[3][1]);

    double A4 = points[3][1] - points[0][1];
    double B4 = points[0][0] - points[3][0];
    double C4 = det(points[3][0],points[3][1],points[0][0],points[0][1]);


    double angle = (points[0][0]-points[1][0])*(points[2][0]-points[1][0]) 
                 + (points[0][1]-points[1][1])*(points[2][1]-points[1][1]);
    if(angle != 0) return false;

    return det(A,B,A3,B3) == 0 && det(A2,B2,A4,B4) == 0;
}