2 задача

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _02.Sum_of_2_arrays
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Write end point: ");
            int end = int.Parse(Console.ReadLine());

            double[] first = new double[end];
            double[] second = new double[end];
            double sum = 0;

            for (int i = 0; i < end; i++)
            {
                first[i] = i + 1;
                second[i] = i + 1;
            }

            for (int i = 0; i < end; i++)
            {
                sum += Math.Pow(first[i], 2) + Math.Pow(second[i], 2);
            }

            Console.WriteLine(sum);;
        }
    }
}