// https://www.facebook.com/abhi.sensharma/posts/1241788872853419

// Subscribed by Abhishek Sharma

import java.io.*;

import java.util.*;

public class Solution {

public static void main(String[] args) {

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, sum = 0;

for(int i = 0; i < n; i ++) {

for(int j = i; j < n; j ++) {

sum += arr[j];

if(sum < 0) count ++;

}

sum = 0;

}

System.out.println(count);

}

}