How to Hide the "WP Total Hacks" Admin Menu

function plt_hide_wp_total_hacks_menus() {
	//Hide the "Settings → WP Total Hacks" menu.
	remove_submenu_page('options-general.php', 'wp-total-hacks');
}

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

Where do I put this code?