#include <math.h>
#include <stdio.h>
#include <string.h>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <set>
using namespace std;
int main()
{
int n;
scanf("%d", &n);
vector<int> val(n);
for (int i=0; i<n; i++)
scanf("%d", &val[i]);
long long res = 0;
long long mult = 0;
for (int i=0; i<n; i++) {
long long sum = 0;
for (int j=i; j<n; j++) {
sum += val[j];
if (sum >= 0) break;
}
if (sum >= 0) {
mult ++;
res += mult * val[i];
} else mult = 0;
}
printf("%lld\n", res);
}
