How do i add 800 dollars to the account myobj1 using the property balance?

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

namespace Assignment2_Nonyelu
{
    public class A2AccountTest
    {
        public static void Main(string[] args)
        {
            //a
            A2Account myObj1 = new A2Account();
            Console.WriteLine("The balance = {0:C}", myObj1.Balance);
            A2Account myObj2 = new A2Account("Mary Johns", 5000.0);
            Console.WriteLine("The balance = {0:C}", myObj2.Balance);

            //b
            myObj1();

            //c
            double a = myObj1.Withdraw(1000.0);
            if(a < 0)
                Console.WriteLine("Insufficient funds");
            Console.WriteLine("The balance = {0:C}", myObj1.Balance);

            a = myObj2.Withdraw(1000.0);
            if (a < 0)
                Console.WriteLine("Insufficient funds");
            Console.WriteLine("The balance = {0:C}", myObj2.Balance);

            //d
            Console.WriteLine("Account Owner: Mary Johns: Balance = nnnnn");
        }
    }
    public class A2Account
    {
        private string owner; //Q1
        private double balance;
        private int transaction;


    //Q2
    public A2Account()
    {
        owner = "Mary Johns";
        balance = 0;
    }
    public A2Account(string s, double d)
    {
        owner = s;
        balance = d;
    }
    
    //Q3
    public double Balance
    {
            get
            {
                return balance;
            }
            set
            {
                balance = value;
            }
    }
    //Q4
    public double Withdraw(double a)
    {
        if (balance >= a)
        {
            transaction++;
            balance -= a;
            return balance;
        }
        else
        {
            return -1;
        }
            //double amount = a;
            //return balance = 0;
    }
    //Q5
    public string ToString()
    {
            return "Account Owner: Mary Johns: Balance = nnnnn" + balance;
    }
    }
}