#!/bin/python

import sys
def max_number(A,i,j):
    biggest = A[i]
    for l in range(j-i):
        if(A[i+1]>biggest):
            biggest = A[i+1]
    return biggest

def solve(A):
    #  Return the sum of S(S(A)) modulo 10^9+7
    B = []
    C=[]
    for k in range(len(A)):
        for i in range(len(A)-k):
            j = i + k 
           
            B.append(max_number(A,i,j))
    for c in range(len(B)):
        for d in range(len(B)-c):
            f = c+d
           
            C.append(max_number(B,d,f))
            
    return sum(C)
   
    
   
    
if __name__ == "__main__":
    n = int(raw_input().strip())
    A = map(int, raw_input().strip().split(' '))
    result = solve(A)
    print result