#include <iostream>
#include <vector>
#include <limits.h>
using namespace std;

int sum[190][90][3];

int solution(vector<int> &arr, int l, int k, int p){
	if(sum[l][k][p]){
		return sum[l][k][p];
	}
	int ans = 0;
	if(arr.size() - l <= k){
		for(int i = l; i < arr.size(); i++){
			ans += arr[i];
		}
		if(p == 2){
			sum[l][k][p] = 0;
			return sum[l][k][p];
		}
		sum[l][k][p] = ans;
		return sum[l][k][p];
	}
	if(p == 1){
		int temp = 0;
		for(int i = 1; i <= k; i++){
			temp += arr[(l-1) + i];
			ans = max(ans, temp + solution(arr, l+i, i, 3-p));
		}
		sum[l][k][p] = ans;
		return sum[l][k][p];
	}
	else{
		int ans = INT_MAX;
		for(int i = 1; i <= k; i++){
			ans = min(ans, solution(arr, l+i, i, 3-p));
		}
		sum[l][k][p] = ans;
		return sum[l][k][p];
	}
}

int main() {
	int n, k, a;
	vector<int> coins;
	cin >> n;
	for(int i = 0; i < n; i++){
		cin >> a;
		coins.push_back(a);
	}
	cin >> k;
	cout << solution(coins, 0, k, 1);
	return 0;
}