#include <bits/stdc++.h>
using namespace std;
const int N = 1e4+5, M = 1e4+5, OO = 0x3f3f3f3f;
typedef long long ll;
#define PI 3.14159265358979323846
#define INF LONG_MAX
const int MOD = 1e9+7;
ll solve (int n, deque<ll> dq) {
ll res = 0;
for (int i=0; i<n; i+=2) res+=dq[i];
return res;
}
int main()
{
int tc; cin>>tc;
while (tc--){
int n; cin>>n;
deque <ll> dq;
for (int i=0,x; i<n; ++i) cin>>x,dq.push_back(x);
ll ans = 0;
for (int i=0; i<n; ++i) {
ans = max(ans,solve(n,dq));
dq.push_back(dq.front());
dq.pop_front();
}
cout<<ans<<endl;
}
return 0;
}
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