#include <stdio.h>
int main (){
	int n,i;
	double a[10000];
	while(scanf("%d",&n)!=EOF){
	int count=0;
	double m=0;
	for(i=0;i<n;i++){
		scanf("%lf",&a[i]);
	}
	for(i=0;i<n;i++){
		if(a[i]>0){
			a[i]=0.5*a[i];
		}
	}
	for(i=0;i<n;i++){
		m+=a[i];
		if(m<0)
		count++;
	}
	printf("%d\n",count);
	}
	}