#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using namespace std;

long long pow1(long long x, long long n, long long mod){
    long long ans = 1;
    while (n){
        if (n%2){
            ans *= x;
            ans %= mod;
        }
        x *= x;
        x %= mod;
        n >>= 1;
    }
    return ans;
}


int main()
{
    long long n, l, t, mod = 998244353, ans;
    cin >> n >> l;
    t = (n+l-1)/l;
    ans = pow1(2, t, mod) -1;
    cout << ans << endl;
}