#include <iostream>
#include <algorithm>
using namespace std;

int main(){
	int currentmax =0;
	int maxsum = 0;
	int n;
	cin >> n;
	int current[n] = {0};
	int arr[n];
	bool secondtime[n][n] = {false};
	for (int i =0; i <n; i++){
		cin >> arr[i];
	}
	for (int i = 0; i < n; i++){
	    for (int k = 0; k < 2; k++){

	        for (int j = i; j < n - i; j++){
    		    current[i] = current[i] + arr[j];
        		if (current[i] < 0){
	        		current[i] = 0;
	    	    }
		        if (current[i] > currentmax){
    		    	currentmax = current[i];
	    	    }
	    	    if (maxsum < currentmax){
		    	    maxsum = currentmax;
	            }
	            for (int j = 0; j < i; j++){
    		    current[i] = current[i] + arr[j];
        		if (current[i] < 0){
	        		current[i] = 0;
	    	    }
		        if (current[i] > currentmax){
    		    	currentmax = current[i];
	    	    }
	    	    if (maxsum < currentmax){
		    	    maxsum = currentmax;
	            }
            }
	    }
	}
}
	cout << maxsum << endl;
	return 0;
}