//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < n; i++)
#define rrep(i,n) for (int i = n-1; i >= 0; i--)
#define rep2(i,a,b) for (int i = a; i < b; i++)
#define rrep2(i,a,b) for (int i = a-1; i >= b; i--)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define minv(v) *min_element(all(v))
#define maxv(v) *max_element(all(v))
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}
template<class T> T pow(T x, T y){if (y == 0) return 1.0;T p = pow(x,y/2);if (y%2 == 0) return p*p;else return p*p*x;}

const int MAX = 200010;

vector<mint> fac(MAX),finv(MAX);

void set_fac(){
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    for (int i = 2; i < MAX; i++){
        fac[i] = fac[i-1]*i;
        finv[i] = finv[i-1] * mint(i).inv();
    }
}

mint cmb_mint(int n, int r){
    if (r < 0 || n < r) return 0;
    return fac[n]*finv[n-r]*finv[r];
}

vector<mint> B(200010);

mint b(int x, int y){
    if (y < 0) B[y] = 0;
    else if (y == 0){
        if (x >= 2) B[y] = 1;
        else B[y] = 0;
    }
    else B[y] = cmb_mint(x+y-2,y) + b(x,y-2);
    return B[y];
}

mint a(int x, int y){
    if (x == 0 || y == 0) return 1;
    if (y == 1){
        if (x == 1) return 2;
        else return x-1;
    }
    return a(x,y-2) + cmb_mint(x+y-2,x-2) + 2*B[y-2];
}

int main(){
    set_fac();
    int n,k; cin >> n >> k;
    b(k,n-k);
    cout << a(k,n-k).val() << endl;
}