#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> P;
int INF = 1e16+7;
int mod = 998244353;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
int mod_pow(int x,int y) {
    int res = 1;
    while(y > 0) {
        if(y%2) {
            res = res*x%mod;
        }
        x = x*x%mod;
        y/=2;
    }
    return res;
}
signed main() {
    int N,L;
    cin >> N >> L;
    N = (N+L-1)/L;
    cout << (mod_pow(2,N)+mod-1)%mod << endl;
}