#include <bits/stdc++.h>
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define LLA(v) (v).rbegin(), (v).rend()
#define SZ(v) (v).size()
#define INT(...)                                                               \
    int __VA_ARGS__;                                                           \
    read(__VA_ARGS__)
#define LL(...)                                                                \
    ll __VA_ARGS__;                                                            \
    read(__VA_ARGS__)
#define DOUBLE(...)                                                            \
    double __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define CHAR(...)                                                              \
    char __VA_ARGS__;                                                          \
    read(__VA_ARGS__)
#define STRING(...)                                                            \
    string __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define VEC(type, name, size)                                                  \
    vector<type> name(size);                                                   \
    read(name)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;
template <typename T> struct edge {
    int to;
    T cost;
    edge(int t, T c) : to(t), cost(c) {}
};
template <typename T> using WGraph = vector<vector<edge<T>>>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;
template <class T> inline vector<T> make_vec(size_t a, T val) {
    return vector<T>(a, val);
}
template <class... Ts> inline auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(a, make_vec(ts...));
}

void read() {}
template <class T> inline void read(T &a) { cin >> a; }
template <class T, class S> inline void read(pair<T, S> &p) {
    read(p.first), read(p.second);
}
template <class T> inline void read(vector<T> &v) {
    for(auto &a : v)
        read(a);
}
template <class Head, class... Tail>
inline void read(Head &head, Tail &...tail) {
    read(head), read(tail...);
}
template <class T> inline void chmax(T &a, T b) { (a < b ? a = b : a); }
template <class T> inline void chmin(T &a, T &b) { (a > b ? a = b : a); }

inline bool iskd(ll a, ll b, ll c) {
    return (a != b && b != c && a != c) &&
           ((b > a && b > c) || (b < a && b < c));
}

ll solve(vector<ll> &a) {
    int n = a.size();
    auto dp = make_vec(n + 1, 0LL);
    for(int i = 3; i <= n; i++) {
        if(iskd(a[i-3], a[i - 2], a[i-1])) {
            chmax(dp[i], dp[i-1]);
            chmax(dp[i], dp[i-3] + a[i-3]);
        }
    }
    return dp[n];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    INT(t);
    while(t--) {
        INT(n);
        VEC(ll, a, n);
        vector<ll> b(n), c(n);
        rep(i, n) b[i] = a[(i + 1) % n];
        rep(i, n) c[i] = a[(i + 2) % n];
        ll res = max(solve(a), max(solve(b), solve(c)));
        cout << res << endl;
    }
}