const MOD: u64 = 998_244_353;

fn read() -> (usize, usize) {
    let mut s = String::new();
    use std::io::Read;
    std::io::stdin().read_to_string(&mut s).unwrap();
    let a = s.trim().split_whitespace().flat_map(|s| s.parse()).collect::<Vec<_>>();
    let (n, m) = (a[0], a[1]);
    assert!(1 <= n && n <= 3000);
    assert!(1 <= m && m <= 3000);
    (n, m)
}

fn solve(n: usize, m: usize) {
    let mut dp = vec![vec![0; m + 1]; n + 1];
    dp[0][0] = 1;
    dp[1][0] = MOD - 1;
    for l in 0..n {
        let mut sum = 0;
        for i in 0..=m {
            dp[l][i] %= MOD;
            let v = dp[l][i];
            dp[l + 1][i] += v;
            sum += v;
        }
        for i in 2..=m {
            let v = (sum - dp[l][i]) % MOD;
            dp[l + 1][i] += v;
            if l + i <= n {
                dp[l + i][i] += MOD - v;
            }
        }
    }
    let mut ans = 1;
    for _ in 0..n {
        ans = ans * (m as u64) % MOD;
    }
    ans = (ans + MOD - dp[n].iter().sum::<u64>() % MOD) % MOD;
    println!("{}", ans);
}

fn main() {
    let (n, m) = read();
    solve(n, m);
}