package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	stdin := bufio.NewScanner(os.Stdin)
	//fmt.Print(">")
	stdin.Scan()
	i, _ := strconv.Atoi(stdin.Text())

	//fmt.Print(">")
	stdin.Scan()
	slice := strings.Split(stdin.Text(), " ")
	if len(slice) != i {
		fmt.Println("少ない")
		return
	}

	Deliciousness := make([]int, 0)
	for _, s := range slice {
		j, _ := strconv.Atoi(s)
		Deliciousness = append(Deliciousness, j)
	}

	max := 0
	//maxindex := ""
	for _, value := range aaa(Deliciousness, "", map[string]int{}) {
		if max < value {
			max = value
			//maxindex = index
		}
	}
	fmt.Println(max)
}

func aaa(List []int, Key string, selected map[string]int) map[string]int {
	for i, a := range List {
		if a < 0 {
			continue
		}
		b := make([]int, len(List))
		copy(b, List)

		newKey := ""
		if Key == "" {
			newKey = strconv.Itoa(i + 1)
			selected[newKey] = b[i]
		} else {
			newKey = Key + "-" + strconv.Itoa(i+1)
			selected[newKey] = selected[Key] + b[i]
		}

		b[i] = -1
		if i-1 >= 0 {
			b[i-1] = -1
		}
		if i+1 < len(b) {
			b[i+1] = -1
		}

		sum := 0
		for _, x := range b {
			sum += x
		}
		if sum < 0 {
			return selected
		}
		aaa(b, newKey, selected)
	}
	return selected
}