---

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;

namespace WindowsFormsApp2
{
    public partial class Form1 : Form
    {
        private Rectangle[] savedRects;
        private Color[] savedColors;

        public Form1()
        {
            InitializeComponent();
            this.DoubleBuffered = true;
            SaveSquares();
        }

        private void SaveSquares()
        {
            Random rand = new Random();
            savedRects = new Rectangle[50];
            savedColors = new Color[50];

            for (int i = 0; i < 50; ++i)
            {
                int w = rand.Next(20, 100);
                int h = rand.Next(20, 100);
                int x = rand.Next(this.ClientSize.Width - w);
                int y = rand.Next(this.ClientSize.Height - h);
                savedRects[i] = new Rectangle(x, y, w, h);
                savedColors[i] = Color.FromArgb(rand.Next(256), rand.Next(256), rand.Next(256));
            }
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            for (int i = 0; i < 50; ++i)
            {
                using (SolidBrush brush = new SolidBrush(savedColors[i]))
                    e.Graphics.FillRectangle(brush, savedRects[i]);
                using (Pen pen = new Pen(Color.Black, 1))
                    e.Graphics.DrawRectangle(pen, savedRects[i].X, savedRects[i].Y, savedRects[i].Width, savedRects[i].Height);
            }
        }

        private void Form1_Resize(object sender, EventArgs e)
        {
            Invalidate();
        }
    }
}