#include<bits/stdc++.h>
 
using namespace std;
 
int main(){
	int n ; cin>>n;
	vector<int>arr(n);
	for(int i = 0 ; i <n ; i++){
		cin>>arr[i];
	}
	int b; cin>>b ; 
    int max_sum =INT_MIN;
	for(int k=0;k<=b;k++){
	int sum = 0 ; 
	for(int j=0 ; j<k;j++) {
		sum+=arr[j];
	}
	int remaining = b-k;
	for(int j = n-1; j>= n-remaining ; j--){
		sum+=arr[j];
	} 
	 max_sum=max(sum , max_sum);
	 //k elements from the start , we need to select b-k elements from the end 
	}
	cout<<max_sum;
	return 0 ; 
}
 
 

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NQo1IC0yIDMgMSAyIAo1Cgo=

5
5 -2 3 1 2 
5