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#include<bits/stdc++.h>
#define ST first
#define ND second
#define ll long long
#define ld long double
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
using namespace std;

const ll  INF = 1e9 + 9;
const ll  MOD = 1e9 + 7;
const long long LINF = (ll)1e18 + 3;

// secik.insert({x, t++});
// secik.erase(secik.lower_bound({x,-1}));
// *secik.find_by_order(x)).first << "\n";
// secik.order_of_key(x)

//random_device device;
//mt19937 gener(device());
//uniform_int_distribution<ll > gen(0,n-1);
//gen(gener); // generate random number

const int SIZE = 5e5 + 5;

ll minxd[SIZE];

int main(){
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	
	int n; cin >> n;
	
	vector<ll> tab(n+1);
	vector<vector<ll> > dp(n+1,vector<ll>(n+1));
	vector<ll> prefsum(n+1),prefsum2(n+1);
	
	for(int i = 0; i < n; i++){
		cin >> tab[i];
		if(i != 0){
			prefsum[i] = prefsum[i-1];
			prefsum2[i] = prefsum2[i-1];
		}
		prefsum[i] += max(tab[i],0ll);
		if(tab[i] < 0) prefsum2[i] += abs(tab[i]);
	}
	
	
	for(int i = 0; i < n; i++)
		for(int j = 0; j < n; j++)
			dp[i][j] = 1e9;
	
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			if(j > i) break;
			if(j == 0){
				ll sum = prefsum[i];
				ll zap = prefsum2[i];
				if(sum >= zap){
					dp[i][j] = i;
				}			
			} else {
				ll sum = prefsum[i] - prefsum[j-1];
				ll zap = prefsum2[i] - prefsum2[j-1];	
				if(sum >= zap){
					dp[i][j] = i - j + minxd[j-1];
				}
			}
		}	
		ll minn = 1e9;
		for(int j = 0; j < n; j++) minn = min(minn,dp[i][j]);	
		minxd[i] = minn;
	}
	
	cout << minxd[n-1] << "\n";
	


	return 0;
}