#include<bits/stdc++.h>
using namespace std;
#include<atcoder/modint>
typedef atcoder::modint998244353 mint;

int main(){
	long long n; cin >> n;
	long long k; cin >> k;
	mint ninv = mint(n).inv();
	vector mat(60, vector(3, vector<mint>(3)));
	mat[0][0][0] = mint(3*n-2)*ninv;
	mat[0][0][1] = -mint(3*n-4)*ninv;
	mat[0][0][2] = mint(n-2)*ninv;
	mat[0][1][0] = 1;
	mat[0][2][1] = 1;
	for (int num=0; num<59; num++){
		for (int i=0; i<3; i++){
			for (int j=0; j<3; j++){
				for (int k=0; k<3; k++){
					mat[num+1][i][j] += mat[num][i][k] * mat[num][k][j];
				}
			}
		}
	}
	vector<mint> a = {ninv, 0, 0};
	for (int num=0; num<60; num++){
		if (k >> num & 1){
			vector<mint> na = {0, 0, 0};
			for (int i=0; i<3; i++){
				for (int j=0; j<3; j++){
					na[i] += mat[num][i][j] * a[j];
				}
			}
			a = na;
		}
	}
	cout << (a[2] + mint(n)).val() << endl;
}