How to Hide Under Construction Admin Menus

function plt_hide_underconstruction_menus() {
	//Hide "Under Construction".
	remove_menu_page('under-construction');
	//Hide "Under Construction → Under Construction".
	remove_submenu_page('under-construction', 'under-construction');
	//Hide "Under Construction → Other Tools".
	remove_submenu_page('under-construction', 'under-construction-plugin-other-tools');
	//Hide "Under Construction → AppSumo".
	remove_submenu_page('under-construction', 'uc_go_appsumo_pro');
}

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

Where do I put this code?