#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }


/*
  x[I] >= 0
  \sum[u\in I] x[I] = A[u]
  minimize \sum[I] x[I]
  
  dual
  \sum[I\ni u] y[u] <= 1
  maximize \sum[u] A[u] y[u]
  
  < -1 ==> useless because 1 + (-1) + 1 = 1
  -1 <= y[u] <= 1
*/

constexpr Int INF = 1001001001001001001LL;

int N;
vector<Int> A;

int main() {
  int trans[2][8][3];
  memset(trans, ~0, sizeof(trans));
  for (int s = 0; s < 2; ++s) {
    for (int p = 0; p < 8; ++p) {
      for (int y = -1; y <= 1; ++y) {
        const int q0 = (s == 0) ? max((p >> 0 & 1) + y, 0) : (p >> 0 & 1);
        const int q1 = (s == 1) ? max((p >> 1 & 1) + y, 0) : (p >> 1 & 1);
        const int q2 =            max((p >> 2 & 1) + y, 0);
        if (q0 <= 1 && q1 <= 1 && q2 <= 1) {
          trans[s][p][1 + y] = q0 << 0 | q1 << 1 | q2 << 2;
        }
      }
    }
  }
  
  for (int numCases; ~scanf("%d", &numCases); ) { for (int caseId = 1; caseId <= numCases; ++caseId) {
    scanf("%d", &N);
    A.resize(N);
    for (int i = 0; i < N; ++i) {
      scanf("%lld", &A[i]);
    }
    
    // max suffix for even/odd/whole ({0, 1}^3)
    Int crt[8], nxt[8];
    fill(crt, crt + 8, -INF);
    crt[0] = 0;
    for (int i = 0; i < N; ++i) {
      fill(nxt, nxt + 8, -INF);
      for (int p = 0; p < 8; ++p) {
        for (int y = -1; y <= 1; ++y) {
          const int q = trans[i & 1][p][1 + y];
          if (~q) {
            chmax(nxt[q], crt[p] + A[i] * y);
          }
        }
      }
      copy(nxt, nxt + 8, crt);
    }
    const Int ans = *max_element(crt, crt + 8);
    printf("%lld\n", ans);
  }
#ifndef LOCAL
  break;
#endif
  }
  return 0;
}