#include <stdio.h>

const int Mod = 998244353;

int main()
{
	int N, M;
	scanf("%d %d", &N, &M);
	
	int i, j;
	long long ans = 0, pow[3001], sum = 0, r_sum[3001] = {}, dp[3001] = {}, tmp[3001][3001];
	for (i = 1, pow[0] = 1; i <= N; i++) pow[i] = pow[i-1] * M % Mod;
	for (j = 2; j <= M; j++) {
		tmp[1][j] = 1;
		r_sum[j] = 1;
		dp[j] = 1;
	}
	for (i = 2, sum = M - 1, ans = pow[N-1]; i <= N; i++) {
		ans += (dp[i] + sum) % Mod * pow[N-i] % Mod;
		for (j = 2; j <= M; j++) {
			tmp[i][j] = sum - r_sum[j];
			if (tmp[i][j] < 0) tmp[i][j] += Mod;
			if (i + j - 1 <= N) dp[i+j-1] += tmp[i][j];
			r_sum[j] += tmp[i][j];
			if (i >= j) r_sum[j] -= tmp[i-j+1][j];
			if (r_sum[j] < 0) r_sum[j] += Mod;
			else if (r_sum[j] >= Mod) r_sum[j] -= Mod;
		}
		for (j = 2; j <= M; j++) sum += tmp[i][j];
		sum = (sum + Mod - dp[i] % Mod) % Mod;
	}
	printf("%lld\n", ans % Mod);
	fflush(stdout);
	return 0;
}