(nested gridview):How to Get parent gridview rowindex on a child gridview link button click

protected void GridView2_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "go")
        
          {

        GridViewRow Gv2Row = (GridViewRow)((LinkButton)e.CommandSource).NamingContainer;
        GridView Childgrid = (GridView)(Gv2Row.Parent.Parent);
       
        GridViewRow Gv1Row = (GridViewRow)(Childgrid.NamingContainer);
        GridView Parentgrid = (GridView)(Gv1Row.Parent.Parent);
        
       foreach (GridViewRow Grid1row in Parentgrid.Rows)
        {
            Label lbl = (Label)(Grid1row.FindControl("Label1"));
            string grid2Rowtext = lbl.Text;
            Response.Write(grid2Rowtext + "<br>");

        }
    }
}