#include <bits/stdc++.h>

using namespace std;

using i64 = long long;

void solve(){
    int n;
    cin >> n;
    vector<int>a(n);
    bool ok = false;
    for (int i = 0;i < n;i ++ ){
        cin >> a[i];
        if(a[i] < 0)ok = true;
    }

    i64 sum = accumulate(a.begin(), a.end(), 0LL);
    
    int manx = *max_element(a.begin(), a.end());
    int minv = *min_element(a.begin(), a.end());

    if(ok){
        i64 ans = 0;
        for(int i = 0;i < n;i ++){
            ans += abs(a[i]);
        }
        cout << ans << "\n";
    }else{
        cout << manx - minv + sum - manx - minv << "\n";      
    }

}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);  

    int T = 1;
    cin >> T;
    while (T --){
        solve();
    }
    return 0;
}