#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MOD = 998244353;

struct mint {
	int x;
	mint() : x(0) {}
	mint(int x) : x(x) {}
	mint operator+(int ot) const { return x + ot >= MOD ? x + ot - MOD : x + ot; }
	mint operator-(int ot) const { return x < ot ? x - ot + MOD : x - ot; }
	mint operator*(int ot) const { return 1ll * x * ot % MOD; }
	mint operator+=(int ot) { return *this = *this + ot; }
	mint operator-=(int ot) { return *this = *this - ot; }
	mint operator*=(int ot) { return *this = *this * ot; }
	operator int() const { return x;}
};
mint mpow(mint a, ll x) {
	mint r = 1;
	while (x) {
		if (x & 1) r *= a;
		a *= a;
		x /= 2;
	}
	return r;
}

int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);

	mint N, M;
	cin >> N.x >> M.x;

	cout << (N - M + 1) * mpow(N + 1, M - 1) << '\n';	
}