import java.io.; 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 total = 0;
    for(int i = 0; i < n; i++){
        int sum = 0;
        for(int j = i; j < n; j++) {
            for (int k = j; k <= j; k++) {
                sum += arr[k];
                if (sum < 0) {
                    total += 1;
                }
            }
        }
    }
    System.out.println(total);
}

}