URAL 1020 Rope

 1 import java.awt.geom.Point2D;
 2 import java.util.Scanner;
 3 
 4 public class P1020
 5 {
 6     public static void main(String args[])
 7     {
 8         try (Scanner cin = new Scanner(System.in))
 9         {
10             while (cin.hasNext())
11             {
12                 int n = cin.nextInt();
13                 double r = cin.nextDouble();
14                 Point2D.Double points[] = new Point2D.Double[n];
15                 for (int i = 0; i < n; i++)
16                     points[i] = new Point2D.Double(cin.nextDouble(), cin.nextDouble());
17                 double result = 2 * Math.PI * r;
18                 if (n > 1)
19                 {
20                     for (int i = 1; i < n; i++)
21                         result += points[i].distance(points[i - 1]);
22                     result += points[n - 1].distance(points[0]);
23                 }
24                 System.out.println(String.format("%.2f", result));
25             }
26         }
27     }
28 }