using System;

public class Program

{

    public static void Main()

    {

    double annualInvestmentAmount = 0;

        int investmentYear = 0;

        double annualInterestRate = 0;

​

        // Input validation loop for Annual Investment Amount

        while (true)

        {

            Console.Write("Enter Annual Investment Amount: ");

            if (double.TryParse(Console.ReadLine(), out annualInvestmentAmount) && annualInvestmentAmount > 0)

            {

                break;

            }

            else

            {

                Console.WriteLine("Invalid input. Please enter a valid positive number for Annual Investment Amount.");

            }

        }

​

        // Input validation loop for Investment Year

        while (true)

        {

            Console.Write("Enter Investment Year (greater than 3): ");

            if (int.TryParse(Console.ReadLine(), out investmentYear) && investmentYear > 3)

            {

                break;

            }

            else

            {

                Console.WriteLine("Invalid input. Please enter a valid integer greater than 3 for Investment Year.");

            }

        }

​

        // Input validation loop for Annual Interest Rate

        while (true)

        {

            Console.Write("Enter Annual Interest Rate (between 0 and 1): ");

            if (double.TryParse(Console.ReadLine(), out annualInterestRate) && annualInterestRate >= 0 && annualInterestRate <= 1)

            {

                break;

            }

            else

            {

                Console.WriteLine("Invalid input. Please enter a valid number between 0 and 1 for Annual Interest Rate.");

            }

        }

​

        // Calculating retirement plan

        double accumulatedInvestment = 0;

        for (int year = 1; year <= investmentYear; year++)

        {

            double endBalance = (accumulatedInvestment + annualInvestmentAmount) * (1 + annualInterestRate);

            Console.WriteLine("Year: " + year + ", Accumulated investment: " + accumulatedInvestment.ToString("C2") + ", End balance: " + endBalance.ToString("C2"));

            accumulatedInvestment = endBalance;

    }

    }

}