How to Hide Smart Slider 3 Admin Menus

function plt_hide_smart_slider_3_menus() {
	//Hide "Smart Slider".
	remove_menu_page('smart-slider3');
	//Hide "Smart Slider → Dashboard".
	remove_submenu_page('smart-slider3', 'smart-slider3');
	//Hide "Smart Slider → Help center".
	remove_submenu_page('smart-slider3', 'smart-slider3-help');
	//Hide "Smart Slider → Go Pro".
	remove_submenu_page('smart-slider3', 'smart-slider3-go-pro');
}

add_action('admin_menu', 'plt_hide_smart_slider_3_menus', 11);

Where do I put this code?