#!/bin/python3

import sys

def solve(A):
    #  Return the length of the longest possible sequence of moves modulo 10^9+7.
    n = len(A)
    b = []
    memo = [[0 for i in range(n)] for j in range(n)]
    for size in range(0, n):
        for i in range(n-size):
            j = i+size
            if size ==0:
                ans = A[i]
            else:
                ans = max(A[i], memo[size-1][i+1])
            memo[size][i] = ans
            
            b.append(ans)
    mirr = b

    nn = len(mirr)
    su = 0

    memo = [[0 for i in range(nn)] for j in range(nn)]
    for size in range(0, nn):
        for i in range(nn-size):
            if size == 0:
                ans = mirr[i]
            else:
                ans = max(mirr[i], memo[size-1][i+1])
            memo[size][i] = ans
            su += ans



    return su


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