#include <iostream>
#include <vector>
using namespace std;

void solve(){
  int n;
  cin >> n;
  long long inf = 1e18;
  vector<long long> dp(6, -inf);
  dp[0] = 0;
  dp[1] = 0;
  for(int i = 0; i < n; i++){
    long long a;
    cin >> a;
    vector<long long> ndp(6, -inf);
    for(int j = 0; j < 3; j++){
      if(j < 2){
        ndp[2 * j + 2] = max(dp[2 * j], dp[2 * j + 1]) + a;
        ndp[2 * j + 3] = max(dp[2 * j], dp[2 * j + 1]) - a;
      }
      ndp[2 * j] = max(ndp[2 * j], dp[2 * j] + a);
      ndp[2 * j + 1] = max(ndp[2 * j + 1], dp[2 * j + 1] - a);
    }
    swap(dp, ndp);
  }
  cout << max(dp[4], dp[5]) << endl;
}

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