Retrive Main Header row and Sub Header from DataGridView using C#

Code to get Main Header row and its sub Header divided within the Datagridview Header. Use of CellPaint event

private void frmCheckGrid_Load(object sender, EventArgs e)
        {
            this.dataGridView1.Columns.Add("Colm1", "Win"); 
            this.dataGridView1.Columns.Add("Colm2", "Loss"); 
            this.dataGridView1.Columns.Add("Colm3", "Win"); 
            this.dataGridView1.Columns.Add("Colm4", "Loss"); 
            this.dataGridView1.Columns.Add("Colm5", "Win"); 
            this.dataGridView1.Columns.Add("Colm6", "Loss"); 
            this.dataGridView1.Columns.Add("Colm7", "Win"); 
            this.dataGridView1.Columns.Add("Colm8", "Loss"); 
            this.dataGridView1.Columns.Add("Colm9", "Win"); 
            this.dataGridView1.Columns.Add("Colm10", "Loss"); 
 
            for (int j = 0; j < this.dataGridView1.ColumnCount; j++)
            { 
                this.dataGridView1.Columns[j].Width = 60; 
            }
 
            this.dataGridView1.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.EnableResizing; 
            this.dataGridView1.ColumnHeadersHeight = this.dataGridView1.ColumnHeadersHeight * 2; 
            this.dataGridView1.ColumnHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.TopCenter; 
            this.dataGridView1.CellPainting += new DataGridViewCellPaintingEventHandler(dataGridView1_CellPainting);            
            this.dataGridView1.Paint += new PaintEventHandler(dataGridView1_Paint); 
            this.dataGridView1.Scroll += new ScrollEventHandler(dataGridView1_Scroll); 
            this.dataGridView1.ColumnWidthChanged += new DataGridViewColumnEventHandler(dataGridView1_ColumnWidthChanged); 
        }

void dataGridView1_ColumnWidthChanged(object sender, DataGridViewColumnEventArgs e)
        { 
            Rectangle rtHeader = this.dataGridView1.DisplayRectangle; 
            rtHeader.Height = this.dataGridView1.ColumnHeadersHeight / 2; 
            this.dataGridView1.Invalidate(rtHeader); 
        } 
 
        void dataGridView1_Scroll(object sender, ScrollEventArgs e)
        { 
            Rectangle rtHeader = this.dataGridView1.DisplayRectangle; 
            rtHeader.Height = this.dataGridView1.ColumnHeadersHeight / 2; 
            this.dataGridView1.Invalidate(rtHeader); 
        } 
 
        void dataGridView1_Paint(object sender, PaintEventArgs e)
        { 
            string[] monthes = { "A", "B", "C", "D", "E" }; 
            for (int j = 0; j < 10; )
            { 
                Rectangle r1 = this.dataGridView1.GetCellDisplayRectangle(j, -1, true); 
                int w2 = this.dataGridView1.GetCellDisplayRectangle(j + 1, -1, true).Width; 
                r1.X += 1; 
                r1.Y += 25; 
                r1.Width = r1.Width + w2 - 2; 
                r1.Height = r1.Height / 2 - 2; 
                e.Graphics.FillRectangle(new SolidBrush(this.dataGridView1.ColumnHeadersDefaultCellStyle.BackColor), r1);               
                StringFormat format = new StringFormat(); 
                format.Alignment = StringAlignment.Center; 
                format.LineAlignment = StringAlignment.Center; 
                e.Graphics.DrawString(monthes[j / 2], 
                    this.dataGridView1.ColumnHeadersDefaultCellStyle.Font, 
                    new SolidBrush(this.dataGridView1.ColumnHeadersDefaultCellStyle.ForeColor), 
                    r1, format); 
                j += 2; 
            } 
        } 
 
        void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
        { 
            if (e.RowIndex == -1 && e.ColumnIndex > -1)
            { 
                Rectangle r2 = e.CellBounds; 
                r2.Y += e.CellBounds.Height / 2; 
                r2.Height = e.CellBounds.Height / 2; 
                e.PaintBackground(r2, true); 
                e.PaintContent(r2);  
                e.Handled = true; 
            } 
        }