ขอความช่วยเหลือหน่อยครับเกี่ยวกับการวนลูป Do - while แบบรับค่าจากคีย์บอร์ด

using System;
namespace Chanatza
{
    class Mounova
    {
        static void Main()
        {
            int a, b, c, d, e, i, avg, sum;
            Console.Write("Input your fisrt number: ");
            a = int.Parse(Console.ReadLine());
            Console.Write("Input your second number: ");
            b = int.Parse(Console.ReadLine());
            Console.Write("Input your third number: ");
            c = int.Parse(Console.ReadLine());
            Console.Write("Input your fourth number: ");
            d = int.Parse(Console.ReadLine());
            Console.Write("Input your fifth number: ");
            e = int.Parse(Console.ReadLine());
            i = 1;
            sum = a + b + c + d + e;
            avg = sum / 5;
            Console.Write("Avg of {0} + {1} + {2} + {3} + {4} = {5}", a, b, c, d, e, avg);
            Console.ReadLine();
        }
    }
}