#include<iostream>
using namespace std;
int a[1005];
int add[1005];
int dp[1005];
int main()
{
	int n;
	cin >> n;
	add[0] = 0;
	for (int i = 1; i <= n; i++)
	{
		cin >> a[i];
		add[i] = add[i - 1] + a[i];
		if (a[i] >= 0)
		{
			dp[i] = 1;
		}
	}

	for (int i = 1; i <= n; i++)
	{
		for (int j = i; j >= 1; j--)
		{
			if (add[i] - add[j] + a[j] >= 0)
			{
				dp[i] = max(dp[j-1] + 1, dp[i]);
			}
		}
	}
	if (add[n] < 0)
	{
		cout << "Impossible";
	}
	else
	{
		cout << dp[n];
	}
	
}