(use '[clojure.string :only (split triml)])

(
    let [
      n_t (read-line) 
      n (Integer/parseInt n_t) 
    ]

  (
    let [
      a_temp (read-line) 
      a_t (split a_temp #"\s+") 
      a (apply vector (map #(Integer/parseInt %) a_t)) 
    ]
    
    (defn thirdloop [a]
            (for [k (range (count a))]    
              (for [i (range (- (count a) k)) :let [j (+ i k)]]                  
                      (apply max (subvec a i (+ j 1))))))
        (prn (reduce + (flatten (thirdloop (apply vector (flatten (thirdloop a)))))))
      
     
    
  )

)