from math import sin, cos, sqrt, atan2, radians


def get_distance_from_home(lat_b, lon_b):
    lat_a = 42.295940
    lon_a = -83.751960

    return distance_lat_lon(lat_a, lon_a, lat_b, lon_b)


def distance_lat_lon(lat_a, lon_a, lat_b, lon_b):

    R = 6373.0
    R = 6373.0
    lat1 = radians(lat_a)
    lon1 = radians(lon_a)
    lat2 = radians(lat_b)
    lon2 = radians(lon_b)
    dlon = lon2 - lon1
    dlat = lat2 - lat1
    a = sin(dlat / 2) ** 2 + cos(lat1) * cos(lat2) * sin(dlon / 2) ** 2
    c = 2 * atan2(sqrt(a), sqrt(1 - a))

    return R * c