#!/bin/python3

import sys

def solve(A):
    #  Return the sum of S(S(A)) modulo 10^9+7
    b=[]
    lis=[]
    b.clear()
    lis.clear()
    l=len(A)
    for k in range(0,l):
        for i in range(0,l-k):
            j=i+k
            lis.clear()
            if j==i:
                b.append(A[i])
            elif j>i:
                for z in range(i,j+1):
                    lis.append(A[z])
                b.append(max(lis))
    return b

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