https://ac.nowcoder.com/acm/contest/76795/B

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> PII;
typedef vector<long long> VI;
#define rep(i,a,n) for (int i=a;i<=n;i++)
#define per(i,a,n) for (int i=a;i>=n;i--)
#define pb(i) push_back(i)
#define int long long
#define INF 0x3f3f3f3f
#define oz  998244353
//#define endl '\n'
#define N 200010
const int mod = 1e9 + 7;


int p[N], si[N];
int find(int x) {
    if (x != p[x]) p[x] = find(p[x]);
    return p[x];
}
//size[find(b)] += size[find(a)];
//p[find(a)] = find(b);



void solve() {
    int n;
    cin >> n;

    VI a(n + 1);
    rep(i, 1, n)cin >> a[i];
    sort(a.begin() + 1, a.end());

    int x = 0, res = a[n];

    rep(i, 1, n - 1) {
        a[i] += x; 
        if (a[i] < 0) {//判断当先数在前面负数累加后是否为负数
            res += a[i];
            x += a[i]; //负数的贡献累加
        }
        else res += a[i];
    }

    cout << res << endl;
}

signed main() {

    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T = 1;
    cin >> T;
    while (T --)

        solve();

    return 0;
}