import java.util.Scanner;
public class Main {
	  public static void main(String[] args) {
	        Scanner sc = new Scanner(System.in);
	        long n = sc.nextLong();
	        long k = sc.nextLong();
	        long mod = 998244353;
	        long [] q = new long [(int)n + 10];
	        long ans = 0;
	        for(int i = (int)k + 1; i > 0; i--){
	        	q[i] = modPow(k, n, mod) - modPow(i - 1,n, mod) - (((k - i + 1) * n) % mod) * modPow(i - 1, n - 1, mod);
	        	q[i] %= mod;
	        	ans += ((q[i] - q[i + 1] + mod) * i) % mod;
	        	ans %= mod;
	        }
	        System.out.println(ans);
	    }
	  public static long modPow(long a, long n, long mod) {
	        long ans = 1;
	        long tmp = a;

	        while(true) {
	            if (n < 1) {
	                break;
	            }
	            if (n % 2 == 1) {
	                ans *= tmp;
	                ans %= mod;
	            }

	            tmp *= tmp;
	            tmp %= mod;

	            n /= 2;
	        }
	        return ans;
	    }


}