//#include<bits/stdc++.h>
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<iostream>
#include<algorithm>
#include<set>
#include<vector>
#include<list>
#include<queue>
#include<cmath>
#include<cstring>
#include<sstream>
#include<cstdio>
#include<ctime>
#include<map>
#include<stack>
#include<string>
using namespace std;
#define ll long long
const int inf = 0x3f3f3f3f;
const int maxn =1e5+10;
int n;
int ans;
int main()
{
	while(~scanf("%d",&n))
	{
		double sum=0;
		ans=0;
		for(int i=1;i<=n;i++)
		{
			double a;
			scanf("%lf",&a);
			if(a>0)a/=2;
			sum+=a;
			if(sum<0)ans++;
		}
		printf("%d\n",ans);
	}
}