How to Hide Counter Box Admin Menus

function plt_hide_counter_box_menus() {
	//Hide the "Wow Plugins" menu.
	remove_menu_page('wow-company');
	//Hide the "Wow Plugins →  Hey" menu.
	remove_submenu_page('wow-company', 'wow-company');
	//Hide the "Wow Plugins → Counter Box" menu.
	remove_submenu_page('wow-company', 'counter-box');
}

add_action('admin_menu', 'plt_hide_counter_box_menus', 11);

Where do I put this code?