(define (System.out.println x)
  (begin
    (display x)
    (newline)
  )
)

(let (
      (N (read))
     )
  (let loop(
            (i 1)
            (foo (list (read)))
            (sum 0)
           )
    (if (< i N)
        (loop (+ i 1) (cons (read) foo) (+ sum (car foo)))
        (let loop2(
                   (j 0)
                   (bar (/ (+ sum (car foo)) 10))
                   (Cnt 0)
                  )
          (if (< j N)
              (if (<= (list-ref foo j) bar)
                  (loop2 (+ j 1) bar (+ Cnt 1))
                  (loop2 (+ j 1) bar Cnt)
              )
              (System.out.println (* Cnt 30))
          )
        )
    )
  )
)