// ---------- begin scannner ----------
#[allow(dead_code)]
mod scanner {
    use std::str::FromStr;
    pub struct Scanner<'a> {
        it: std::str::SplitWhitespace<'a>,
    }
    impl<'a> Scanner<'a> {
        pub fn new(s: &'a String) -> Scanner<'a> {
            Scanner {
                it: s.split_whitespace(),
            }
        }
        pub fn next<T: FromStr>(&mut self) -> T {
            self.it.next().unwrap().parse::<T>().ok().unwrap()
        }
        pub fn next_bytes(&mut self) -> Vec<u8> {
            self.it.next().unwrap().bytes().collect()
        }
        pub fn next_chars(&mut self) -> Vec<char> {
            self.it.next().unwrap().chars().collect()
        }
        pub fn next_vec<T: FromStr>(&mut self, len: usize) -> Vec<T> {
            (0..len).map(|_| self.next()).collect()
        }
    }
}
// ---------- end scannner ----------

use std::io::Write;

fn main() {
    use std::io::Read;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut sc = scanner::Scanner::new(&s);
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    run(&mut sc, &mut out);
}

fn kadomatsu(a: &[u64]) -> bool {
    a[0] != a[1] && a[1] != a[2] && a[2] != a[0] && (a[1] > a[0].max(a[2]) || a[1] < a[0].min(a[2]))
}

fn run<W: Write>(sc: &mut scanner::Scanner, out: &mut std::io::BufWriter<W>) {
    let t: usize = sc.next();
    for _ in 0..t {
        let n: usize = sc.next();
        let mut a: Vec<u64> = sc.next_vec(n);
        let mut ans = 0;
        for _ in 0..3 {
            let mut dp = vec![0; n + 1];
            for i in (0..=(n - 3)).rev() {
                dp[i] = dp[i + 1];
                if kadomatsu(&a[i..(i + 3)]) {
                    dp[i] = dp[i].max(dp[i + 3] + a[i]);
                }
            }
            ans = ans.max(dp[0]);
            a.rotate_left(1);
        }
        writeln!(out, "{}", ans).ok();
    }
}