Как определить границы памяти стороннего процесса?

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
 
namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
 
        const int PROCESS_WM_READ = 0x0010;
        const int PROCESS_ALL_ACCESS = 0x1F0FFF;
 
        [DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);
 
        [DllImport("kernel32.dll")]
        public static extern bool ReadProcessMemory(int hProcess, int lpBaseAddress, byte[] lpBuffer, int dwSize, ref int lpNumberOfBytesRead);
 
        [DllImport("Kernel32")] // Запись в память
        public static extern Int32 WriteProcessMemory(IntPtr hProcess, int lpBaseAddress, byte[] lpBuffer, int nSize, out int lpNumberOfBytesWritten);
 
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
 
 
            Process process = Process.GetProcessesByName("notepad")[0];
            IntPtr processHandle = OpenProcess(PROCESS_WM_READ, false, process.Id);
 
            int bytesRead = 0;
            byte[] buffer = new byte[4];
 
            ReadProcessMemory((int)processHandle, 0x00399900, buffer, buffer.Length, ref bytesRead);
 
            MessageBox.Show(Encoding.ASCII.GetString(buffer));
 
 
        }
    }
}