<?php
    $cache = array();

    function fibonacci($nr) {
        global $cache;

        if (isset($cache[$nr])) {
            return $cache[$nr];
        }
        switch ($nr) {
            case 0:
                die("Invalid Nr\n");
            case 1:
                return 1;
            case 2:
                return 1;
            default:
                $r = fibonacci($nr - 2) + fibonacci($nr - 1);
                $cache[$nr] = $r;
                return $r;
        }
    }

    echo fibonacci($argv[1])."\n";
?>