import java.io.; import java.util.; import java.text.; import java.math.; import java.util.regex.*; import java.io.IOException; import java.util.Scanner;

public class Solution { public static void main(String[] args) throws IOException { 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 x = 0; x < n; x++) {
        int sum = 0;
        for (int y = x; y < n; y++) {
            sum += arr[y];
            if (sum < 0) {
                count++;
            }
        }
    }

    System.out.println(count);
    sc.close();
}

}