#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T &x) {
  x = 0;
  char ch = getchar();
  long long fh = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') fh = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  x *= fh;
}
template <typename T>
void write(T x) {
  if (x < 0) x = -x, putchar('-');
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
template <typename T>
void writeln(T x) {
  write(x);
  puts("");
}
long long n, a[100005];
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    cin >> n;
    for (long long i = 1; i <= n; i++) cin >> a[i];
    long long x = 0;
    for (long long i = n; i >= 1; i--)
      if (a[i] < 0)
        x += -a[i];
      else if (x >= a[i])
        x -= a[i];
      else
        x = 0;
    cout << x << endl;
  }
  return 0;
}
