const MOD: usize = 998244353;

fn solve() -> usize {
    let mut temp = String::new();
    std::io::stdin().read_line(&mut temp).ok();
    let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = temp[0];
    let x = temp[1];
    let cnt = n / x;
    let mut ret = if x % 2 == 0 { cnt * x / 2 } else if cnt % 2 == 0 { cnt * x / 2 } else { cnt * x / 2 + 1 };
    if n - cnt * x > 0 {
        ret += (n - cnt * x) / 2;
        if (n - cnt * x) % 2 == 1 {
            if cnt % 2 == 0 {
                ret += 1;
            }
        }
    }
    ret
}

fn main() {
    let mut t = String::new();
    std::io::stdin().read_line(&mut t).ok();
    let t: usize = t.trim().parse().unwrap();
    let mut result = Vec::with_capacity(t);
    for _ in 0..t {
        result.push(solve());
    }
    for &v in result.iter() {
        println!("{}", v % MOD);
    }
}