import java.io.; import java.util.; import java.text.; import java.math.; import java.util.*;

public class Solution {

public static void main(String[] args) {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
    Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] arr=new int[n];
    for(int i=0;i<n;i++){
        arr[i]=sc.nextInt();
    }
    int negCount=0;
    for(int i=0;i<n;i++){
        int num=0;

        for(int j=i;j<n;j++){
            num+=arr[j];
             if(num<0){
            negCount++;
        }
        }
    }
    System.out.println(negCount);
}

}