How to Hide the "P3 Plugin Profiler" Admin Menu

function plt_hide_p3_profiler_menus() {
	//Hide the "Tools → P3 Plugin Profiler" menu.
	remove_submenu_page('tools.php', 'p3-profiler');
}

add_action('admin_menu', 'plt_hide_p3_profiler_menus', 11);

Where do I put this code?