#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int T;
	cin >> T;
	while (T--) {
		int N;
		scanf("%d", &N);
		vector<int> A(N);
		REP(i, N) scanf("%d", &A[i]);
		
		vector<ll> dp;
		ll ans = 0;
		REP(offset, 3) {
			dp.assign(N + 1, 0);
			REP(i, N) {
				const int p = (i + offset) % N;
				
				auto kadomatsu = [](int a, int b, int c) -> bool {
					if (a == c) return false;
					if (a > b && b < c) return true;
					if (a < b && b > c) return true;
					return false;
				};
				
				chmax(dp[i + 1], dp[i]);
				if (i + 3 <= N && kadomatsu(A[p], A[(p + 1) % N], A[(p + 2) % N])) chmax(dp[i + 3], dp[i] + A[p]);
			}
			chmax(ans, dp[N]);
		}
		printf("%lld\n", ans);
	}
}