import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;

public class Main {
	static BufferedReader br;
	static PrintWriter pw;

	public static void main(String[] args) throws Exception {
		br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		pw = new PrintWriter(System.out);
		for (int i = 0; i < t; i++) {
			solve();
		}
		br.close();
		pw.flush();
	}

	static void solve() throws Exception {
		int n = Integer.parseInt(br.readLine());
		String[] sa = br.readLine().split(" ");
		int[] a = new int[n + 2];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}

		long[][] dp = new long[n + 3][3];
		for (int i = 3; i < n + 3; i++) {
			for (int j = 0; j < 3; j++) {
				dp[i][j] = Math.max(dp[i][j], dp[i - 1][j]);
				dp[i][j] = Math.max(dp[i][j], dp[i - 2][j]);
			}

			int[] b = new int[3];
			for (int j = 1; j <= 3; j++) {
				b[j - 1] = a[(i - j) % n];
			}
			if (check(b)) {
				if (i < 6) {
					dp[i][i - 3] = a[i - 3];
				} else {
					for (int j = 0; j < 3; j++) {
						dp[i][j] = Math.max(dp[i][j], dp[i - 3][j] + a[i - 3]);
					}
				}
			}
		}
		long ans = 0;
		for (int i = 0; i < 3; i++) {
			ans = Math.max(ans, dp[n + i][i]);
		}
		pw.println(ans);
	}

	static boolean check(int[] a) {
		if (a[0] != a[2]) {
			if (a[0] < a[1] && a[1] > a[2]) return true;
			if (a[0] > a[1] && a[1] < a[2]) return true;
		}
		return false;
	}
}