Programmer Andrey is very lucky. The Governor-General of Jamaica invited him to visit this wonderful island. The whole trip, including plenty of entertainment, will be completely free for Andrey. He will only have to help the Jamaican Ministry of Transport and write a small program.

The point is that the Jamaican government decided to construct a new network of expressways, in order to boost the economic growth of the country. Each two cities are to be connected by a road going along a straight line. One road may connect several cities if they lie on the same straight line. Jamaican economists are sure that the new network will minimize transportation expenses. In order to estimate the cost of the project, it is required to determine the total length of the roads to be constructed, and this is the job for Andrey.

The first line contains the number n of cities in Jamaica (1 ≤ n ≤ 300). The next n lines contain the coordinates of the cities. In each of these lines, there are two integers x_i and y_i separated by a space (0 ≤ x_i, y_i ≤ 10000). There are no cities with coinciding coordinates.

Output the total length of the roads rounded to the nearest integer.