mod my {
    #[macro_export]
    macro_rules! scan {
        ($r:expr, [$t:tt; $n:expr]) => (
            (0..$n).map(|_| scan!($r, $t)).collect::<Vec<_>>()
        );
        ($r:expr, ($($t:tt),*)) => (
            ($(scan!($r, $t)),*)
        );
        ($r:expr, $t:ty) => ({
            std::str::from_utf8(&scan($r)).unwrap().parse::<$t>().unwrap()
        });
    }

    pub mod io {
        use std::io::{BufRead, ErrorKind};

        pub fn scan<R: BufRead>(r: &mut R) -> Vec<u8> {
            let mut buf = Vec::new();
            loop {
                let (done, used) = {
                    let available = match r.fill_buf() {
                        Ok(n) => n,
                        Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
                        Err(e) => panic!(e), 
                    };
                    match available.iter().position(u8::is_ascii_whitespace) {
                        Some(i) => {
                            buf.extend_from_slice(&available[..i]);
                            (buf.len() > 0, i + 1)
                        }
                        None => {
                            buf.extend_from_slice(available);
                            (false, available.len())
                        }
                    }
                };
                r.consume(used);
                if done || used == 0 {
                    return buf;
                }
            }
        }
    }
}

use std::io::{BufRead, Write};
use my::io::scan;

fn run<R: BufRead, W: Write>(reader: &mut R, writer: &mut W) {
    for _ in 0..scan!(reader, usize) {
        let n = scan!(reader, usize);
        let mut a = scan!(reader, [usize; n]);
        a.extend_from_slice(&a[..3].to_vec());

        let mut ans = 0;
        let mut dp = vec![vec![0; 3]; n + 3];
        for (i, a) in a.windows(3).enumerate() {
            for j in 0..3 {
                dp[i + 1][j] = dp[i + 1][j].max(dp[i][j]);
            }
            if a[0] == a[2] { continue; }
            if a[0] > a[1] && a[1] < a[2] || a[0] < a[1] && a[1] > a[2] {
                for j in 0..3 {
                    if i < j || n + j <= i + 2 { continue; }
                    let next = dp[i][j] + a[0];
                    dp[i + 3][j] = dp[i + 3][j].max(next);
                    ans = ans.max(next);
                }
            }
        }
        writeln!(writer, "{}", ans).ok();
    }
}

fn main() {
    let (stdin, stdout) = (std::io::stdin(), std::io::stdout());
    let reader = &mut std::io::BufReader::new(stdin.lock());
    let writer = &mut std::io::BufWriter::new(stdout.lock());
    run(reader, writer);
}