#include<iostream>
#include<algorithm>
#include<string>
#include<vector>
#include<iomanip>
#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP(i,n,0)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 100000000
using namespace std;

int main(){
	int n;
	cin >>n;
	int a[n];
	int i;
	rep(i,n)
		cin >> a[i];

	int dp[n+1];
	rep(i,n+1)
		dp[i] = 0;
	dp[1] = a[0];

	int j;
	for(i=2; i <= n; i++){
		int temp=-INF;
		rep(j,4){
			switch(j){
				case 0:
					temp = max(temp, dp[i-1] + a[i-1]);
					break;
				case 1:
					temp = max(temp, dp[i-1] - a[i-1]);
					break;
				case 2:
					temp = max(temp, dp[i-1] * a[i-1]);
					break;
				case 3:
					if(a[i-1] != 0)
						temp = max(temp, dp[i-1] / a[i-1]);
					break;
				default:
					break;
			}
			dp[i] = temp;
		}
	}

	cout << dp[n] << endl;

	return 0;
}