using System;

​

public class Program

{

    public static void Main()

    {

        bool loop = true;

        int change = 0;

        int quarters;

        int dimes;

        int nickles;

        int pennies;

        while (loop)

        {

            Console.WriteLine("how much change do you need to return?");

            string input = Console.ReadLine();

            if (Int32.TryParse(input, out change))

            {

                loop = false;

            }

            else

            {

                Console.WriteLine("invalid entry");

                loop = true;

            }

​

            if (change < 1)

            {

                Console.WriteLine("invalid entry");

                loop = true;

            }

        }

    //How many quaters?

   quarters = HowMany(change, 25);

    Console.WriteLine("quarters: " + quarters);

    change = ChangeRemaining(change, quarters, 25);

    //howmany dimes

    dimes = HowMany(change, 10);

    Console.WriteLine("Dimes: " + dimes);

    change = ChangeRemaining(change, dimes, 10);

    //how many nickels

   nickles = HowMany(change, 15);

    Console.WriteLine("Nickles: " + nickles);

    change = ChangeRemaining(change, nickles, 15);

        //how many pennies

        pennies = HowMany(change, 1);

    Console.WriteLine("pennies: " + pennies);

    change = ChangeRemaining(change, pennies, 1);

    }

​

    static int HowMany(int change, int val)

    {

        int count = change / val;

        return count;

    }

static int ChangeRemaining(int change, int count, int val)

{

    int r = change - count + val;

        return r;

   }

}

​