(set! *warn-on-reflection* true)
(set! *unchecked-math* :warn-on-boxed)

(def loop-count 1000000)
(def expected-checksum 3875007)
(def digits [3 1 4 1 5 9 2 6])

(defn configured-loop-count []
  (try
    (let [line (read-line)
          value (Integer/parseInt (.trim ^String line))]
      (if (pos? value) value loop-count))
    (catch Exception _
      loop-count)))

(defn array-index-loop [limit]
  (loop [i 0
         acc 7]
    (if (< i limit)
      (let [next (+ acc (nth digits (rem i 8)))
            bounded (if (> next 1000000000)
                      (- next 1000000000)
                      next)]
        (recur (inc i) bounded))
      acc)))

(let [result (array-index-loop (configured-loop-count))]
  (println result)
  (System/exit (if (= result expected-checksum) 0 1)))