#include <bits/stdc++.h>

using namespace std;

#define int long long
using i64 = long long;

typedef pair<int, int> PII;
typedef pair<int, char> PIC;
typedef pair<double, double> PDD;
typedef pair<int, PII> PIII;
typedef pair<int, pair<int, bool>> PIIB;

const int N = 10;
const int maxn = 1e6 + 10;
const int mod = 998244353;
const int mod1 = 954169327;
const int mod2 = 906097321;
const int INF = 0x3f3f3f3f3f3f3f3f;

void solve()
{
    int n;
    cin >> n;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i ++ ) cin >> a[i];
    sort(a.begin() + 1, a.end());
    int ans = 0;
    for (int i = 1; i <= n; i ++ )
    {
        if (i == n) ans += a[i];
        else if (i == 1) ans -= a[i];
        else ans += abs(a[i]);
    }
    cout << ans << '\n';
}

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

    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
}