#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>
#include <set>
#include <sstream>

using namespace std;


int main() {
	int i, j;
	int n;
	vector<long long >a;
	vector<vector<long long>>dp(1000, vector<long long>(4, 0));


	cin >> n;

	for (i = 0; i < n; i++) {
		long long num;
		cin >> num;
		a.push_back(num);
	}

	dp[0][0] = a[0]; dp[0][1] = a[0]; dp[0][2] = a[0]; dp[0][3] = a[0];



	for (i = 1; i < n; i++) {
		
		dp[i][0] = max({ dp[i - 1][0], dp[i - 1][1], dp[i - 1][2], dp[i - 1][3] }) + a[i];
		dp[i][1] = max({ dp[i - 1][0], dp[i - 1][1], dp[i - 1][2], dp[i - 1][3] }) - a[i];
		dp[i][2] = max({ dp[i - 1][0], dp[i - 1][1], dp[i - 1][2], dp[i - 1][3] }) * a[i];
		
		if (a[i] != 0) {
			dp[i][3] = max({ dp[i - 1][0], dp[i - 1][1], dp[i - 1][2], dp[i - 1][3] }) / a[i];
		}

	}


	cout << max({ dp[n - 1][0], dp[n - 1][1], dp[n - 1][2], dp[n - 1][3] }) << endl;











	getchar();
	getchar();
	return 0;
}