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 count = 0;
    for (int i = 0; i < n; i++) {
      int sum = 0;
      for (int j = i; j < n; j++) {
        sum += arr[j];
        if (sum < 0) {
          count ++;
        }
      }
    }
    System.out.println(count);
    sc.close();
}

}