import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // Create scanner object for input
        Scanner scanner = new Scanner(System.in);

        // Read the number of locations
        int n = scanner.nextInt();

        // Initialize arrays to store the x and y coordinates
        int[] xCoordinates = new int[n];
        int[] yCoordinates = new int[n];

        // Loop to read and store the coordinates
        for (int i = 0; i < n; i++) {
            // Read the input for each location
            xCoordinates[i] = scanner.nextInt();
            yCoordinates[i] = scanner.nextInt();
        }

        // Variable to store the minimum sum of distances
        double min = 100000000;

        // Outer loop to calculate the sum of distances for each location
        for (int i = 0; i < n; i++) {
            double temp = 0;
            for (int j = 0; j < n; j++) {
                int xDist = Math.abs(xCoordinates[i] - xCoordinates[j]);
                int yDist = Math.abs(yCoordinates[i] - yCoordinates[j]);
                temp += Math.sqrt((double) (xDist * xDist) + (double) (yDist * yDist));
            }
            min = Math.min(temp, min);
        }

        // Print the minimum sum of distances
        System.out.println(min);

        // Close the scanner
        scanner.close();
    }
}