def main():
    candidate_num = int(input())
    votes = [int(i) for i in input().split()]
    deposit_pay_line = sum(votes) / 10
    deposit_pay_num = 0
    for vote in votes:
        #print(vote, deposit_pay_line)
        if vote <= deposit_pay_line:
            deposit_pay_num += 1

    print(30 * deposit_pay_num)


if __name__ == '__main__':
    main()