def s(a_list):
    comp = []
    max_n = len(a_list)
    for k in range(0, max_n):
        for i in range(0, max_n-k):
            j = i + k
            s_max = max(a_list[i:j+1])
            comp.append(s_max)
    return comp


def solve(a):
    s1 = s(a)
    s2 = s(s1)
    return sum(s2)

if __name__ == "__main__":
    n = int(input().strip())
    a = list(map(int, input().strip().split(' ')))
    result = solve(a)
    print(result)