How to Hide the "Unused Media" Admin Menu

function plt_hide_gogasys_unused_media_cleaner_menus() {
	//Hide the "Unused Media" menu.
	remove_menu_page('gogasys-unused-media-cleaner');
}

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

Where do I put this code?