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

def calculate_distance(lat1, lon1, lat2, lon2):
    lat1 = radians(lat1)
    lon1 = radians(lon1)
    lat2 = radians(lat2)
    lon2 = radians(lon2)

    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))
    distance = 6371 * c

    return distance

lat1, lon1 = 40.7128, -74.0060
lat2, lon2 = 34.0522, -118.2437

distance = calculate_distance(lat1, lon1, lat2, lon2)

print("Distance between New York City and Los Angeles:", distance, "km")