#include <bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

const int mod = 998244353;

int power(int a, int b) {
	int r = 1;
	for (; b; b >>= 1, (a *= a) %= mod)
		if (b & 1)
			(r *= a) %= mod;
	return r;
}

const int N = 3000 + 7;

int fac[N];
int inv[N];

int C(int n, int k) {
	if (0 <= k && k <= n) {
		return fac[n] * inv[k] % mod * inv[n - k] % mod;
	}
	return 0;
}

int n, m;
int pv[N][2];
int dp[N][2];

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	fac[0] = 1;
	for (int i = 1; i < N; i++)
		fac[i] = fac[i - 1] * i % mod;
	
	inv[N - 1] = power(fac[N - 1], mod - 2);
	for (int i = N - 2; i >= 0; i--)
		inv[i] = inv[i + 1] * (i + 1) % mod;
	
	cin >> n >> m;

	int ans = 1;

	pv[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j <= i; j++)
			for (int k : {0, 1})
				dp[j][k] = 0;

		for (int j = 1; j <= i; j++) {
			for (int k : {0, 1}) {
				dp[j][k] += pv[j - 1][k ^ 1];
				if (j < i) {
					dp[j][k] += pv[j][k] * ((m - 2) * j % mod + mod - (i - 1 - j)) % mod;
				}
				dp[j][k] %= mod;
			}
		}

		for (int j = 0; j <= i; j++) {
			for (int k : {0, 1}) {
				ans += dp[j][k] * C(n, i) % mod;
				ans %= mod;
				pv[j][k] = dp[j][k];
			}
		}
	}

	cout << ans << '\n';
	
	return 0;
}