use std::io::{Write, BufWriter};
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes.by_ref().map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr,) => {};
    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) };
    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };
    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
}

const MOD: i64 = 998_244_353;

// https://yukicoder.me/problems/no/1771 (3)
// https://yukicoder.me/problems/no/1772 (3.5)
// 4000^2 が許される。以下の 5 種類の遷移に分けて DP:
// 1. “” (if x == y)
// 2. “AB” + ?? (x-1, y)
// 3. “BA” + ?? (x, y-1)
// 4. “AA” + ?? (x-1, y-1)
// 5. “BB” + ?? (x-1, y-1)
fn main() {
    let out = std::io::stdout();
    let mut out = BufWriter::new(out.lock());
    macro_rules! puts {($($format:tt)*) => (let _ = write!(out,$($format)*););}
    input! {
        q: usize,
        xy: [(usize, usize); q],
    }
    const W: usize = 4000;
    let mut dp = vec![vec![0; W + 1]; W + 1];
    dp[0][0] = 1;
    for i in 0..W + 1 {
        for j in 0..W + 1 {
            if i + j == 0 { continue; }
            let mut me = 0;
            if i == j {
                me += 1;
            }
            if i > 0 {
                me += dp[i - 1][j];
            }
            if j > 0 {
                me += dp[i][j - 1];
            }
            if i > 0 && j > 0 {
                me += 2 * dp[i - 1][j - 1];
            }
            dp[i][j] = me % MOD;
        }
    }
    for (x, y) in xy {
        puts!("{}\n", dp[x][y]);
    }
}