#include <iostream>
#include <vector>
#include <cmath>
#include <fstream>
#include <algorithm>
#include <queue>
#include <functional>
#include <map>
#include <set>
using namespace std;


typedef vector<int> tVI;
typedef set<int> tSI;


struct rect
{
	int from;
	int height;

	rect(int f, int h):from(f), height(h)
	{ }
};

bool operator<(const rect &a, const rect &b)
{
	return a.height < b.height;
}


ifstream in("histogram.in");


typedef priority_queue<rect> tPQ;


int main()
{
	int n;
	while (in >> n)
	{
		if (!n) break;

		tVI v;
		for (int i=0; i<n; i++)
		{
			int tmp;
			in >> tmp;
			v.push_back(tmp);
		}

		
		long long A = 0;	
		tPQ p;
		tSI s;
		if (v[0]) 
		{
			p.push(rect(0, v[0]));
//			s.insert(v[0]);
		}

		
		for (int cur=1; cur<(int)v.size(); cur++)
		{
			while (!p.empty())
			{
				if (p.top().height <= v[cur]) break;

				// sonst ausrechnen und rausnehmen
				long long test = (long long) ((long long)cur-p.top().from) * p.top().height;
				if (test > A) A = test;

				rect r = p.top();
//				s.erase(p.top().height);
				p.pop();
				if (v[cur]) p.push(rect(r.from, v[cur]));
			}
			
			if (p.empty())
			{
				p.push(rect(cur,v[cur]));
//				s.insert(v[cur]);
			}
			else if (p.top().height < v[cur])
			{
				p.push(rect(cur,v[cur]));
//				s.insert(v[cur]);
			}
			else if (p.top().height == v[cur]);
			else
			{
				if (s.find(v[cur]) != s.end());
				else
				{
					p.push(rect(cur, v[cur]));	
//					s.insert(v[cur]);
				}
			}
			
		}

		while (!p.empty())
		{
				long long test = (long long) ((long long) v.size()-p.top().from) * p.top().height;
				if (test > A) A = test;
				p.pop();
		}

		cout << A << endl;	
	}
	
	return 0;
}