java
    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 countOfNegativeSubArrays = 0;
        int ptr1 = 0;
        int ptr2 = 0;
        
        int sw = Arrays.copyOfRange(arr, ptr1, ptr2+1).length; // default sliding-w width of 1
        while(sw <= arr.length) {
            for (int i = 0; i < arr.length && ptr2+i+1 <= arr.length; i++) {
                // sliding through the array.
                int[] subArr = Arrays.copyOfRange(arr, ptr1+i, ptr2+i+1);
                
                /**
                    debugging:
                    
                    System.out.printf("from %d to %d\n", ptr1+i, ptr2+i);
                    System.out.println(Arrays.toString(subArr));
                    System.out.println("--------------");
                */
                
                int sum = Arrays.stream(subArr).sum();
                if(sum < 0) {
                    countOfNegativeSubArrays++;
                }
                // 0 : 0
                // 1 : 1
                // 2 : 2
                
                // 0 : 1
                // 1 : 2
                
            }
            // Update the sliding-window width
            sw = Arrays.copyOfRange(arr, ptr1, ++ptr2).length+1;
        }
        
        
        System.out.println(countOfNegativeSubArrays);
    }