using System;
using System.Threading;
using System.Globalization;

namespace TestOfCSharp
{
    class Program
    {
        static void Main(string[] args)
        {
            Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
            string[] input = Console.ReadLine().Split(' ');
            int N = int.Parse(input[0]);
            int R = int.Parse(input[1]);
            double sum = 0;
            for (int i = 0; i < N; i++)
            {
                input = Console.ReadLine().Split(' ');
                sum += double.Parse(input[0]) + double.Parse(input[1]);
            }
            sum += 2 * Math.PI * R;
            Console.WriteLine("{0:F2}", sum);
        }
    }
}

Edited by author 20.12.2013 05:18

(pi*r^2)

Edited by author 09.02.2017 18:21

> sum += double.Parse(input[0]) + double.Parse(input[1]);

How it should work? Google "points distance formula".