//Write a program that reads five integer numbers and prints their sum. If an invalid number is entered the program should prompt the user to enter another number(only once)

​

using System;

public class Program

{

    public static void Main()

    {

        int firstNumber;

            int secondNumber;

            int thirdNumber;

            int forthNumber;

            int fifthNumber;

            Console.WriteLine("Input the first number:");

            string a = Console.ReadLine();

            if (!int.TryParse(a, out firstNumber))

            {

                Console.WriteLine("Value is not a number, try again");

                a = Console.ReadLine();

​

            }

            Console.WriteLine("Input the second number:");

            string b = Console.ReadLine();

            if (!int.TryParse(b, out secondNumber))

            {

                Console.WriteLine("Value is not a number, try again");

                b = Console.ReadLine();

            }

            Console.WriteLine("Input the third number:");

            string c = Console.ReadLine();

            if (!int.TryParse(c, out thirdNumber))

            {

                Console.WriteLine("Value is not a number, try again");

                c = Console.ReadLine();

            }

            Console.WriteLine("Input the forth number:");

            string d = Console.ReadLine();

            if (!int.TryParse(d, out forthNumber))

            {

                Console.WriteLine("Value is not a number, try again");

                d = Console.ReadLine();

            }

            Console.WriteLine("Input the fifth number:");

            string e = Console.ReadLine();

            if (!int.TryParse(e, out fifthNumber))

            {

                Console.WriteLine("Value is not a number, try again");

                e = Console.ReadLine();

            }

            Console.WriteLine($"The sum of the number is: {Sum1(firstNumber, secondNumber, thirdNumber, forthNumber, fifthNumber)}");

    }

    static int Sum1(int a, int b, int c, int d, int e)

        {

            return a + b + c + d + e;

        }

}