#!/bin/python

import sys


def solveSSA(A):
    dlist={}
    B = solveSA(A)
    #print B
    SB = solveSA(B)
    #print SB
    return sum(SB)

def solveSA(A):
    B=[]
    #if A in dlist:
    #    return dlist[A]
    for k in range(0,len(A)):
        for i in range(0,len(A)-k):
            j=i+k
            maxval =0
            for x in range(i,j+1):
                if(maxval<A[x]):
                    maxval = A[x]
            B.append(maxval)
    #dlist[A]=B
    return B
    #  Return the sum of S(S(A)) modulo 10^9+7.

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