func_code_string: #include <bits/stdc++.h>   using namespace std;   long long int MAX3(long long int x, long long int y, long long int z) {     long long int t = max(x, y);     return max(t, z);   }   long long int power(long long int x, long long int n) {     long long int i, ans = 1;     for (i = 1; i <= (n); i += 1) {       ans = ans * x;     }     return ans;   }   void solve() {     long long int n, i, sum = 0;     vector<long long int> a;     cin >> n;     for (i = 0; i < (n); i += 1) {       long long int x;       cin >> x;       a.push_back(x);       if (i % 2 == 0) sum += x;     }     vector<long long int> a1, a2;     long long int m1 = 0, m2 = 0;     for (i = 0; i < (n - 1); i += 1) {       long long int t = -a[i] + a[i + 1];       i++;       a1.push_back(t);     }     for (i = 1; i < (n - 1); i += 1) {       long long int t = -a[i + 1] + a[i];       i++;       a2.push_back(t);     }     long long int s = a1.size();     long long int max_so_far = 0;     long long int max_ending_here = 0;     for (i = 0; i < (s); i += 1) {       max_ending_here += a1[i];       max_so_far = max(max_so_far, max_ending_here);       if (max_ending_here < 0) max_ending_here = 0;     }     m1 = max_so_far;     max_so_far = 0;     max_ending_here = 0;     s = a2.size();     for (i = 0; i < (s); i += 1) {       max_ending_here += a2[i];       max_so_far = max(max_so_far, max_ending_here);       if (max_ending_here < 0) max_ending_here = 0;     }     m2 = max_so_far;     long long int ans = max(m1, m2);     cout << ans + sum << endl;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int t;     cin >> t;     while (t--) {       solve();     }     return 0;   }   