#!/bin/python

import sys

def solve(A):
    #  Return the sum of S(S(A)) modulo 10^9+7.
    B= []
    for k in range(len(A)):
        for i in range(len(A)-k):
            B.append(max(A[i:i+k+1]))
    A = B[:]
    B= []
    for k in range(len(A)):
        for i in range(len(A)-k):
            B.append(max(A[i:i+k+1]))
    return sum(B)

if __name__ == "__main__":
    n = int(raw_input().strip())
    A = map(int, raw_input().strip().split(' '))
    result = solve(A)
    print result