#include <algorithm>
#include <bitset>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <cctype>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <limits>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
int mod = 998244353;
using namespace std;
#define int long long
signed main() {
    long long N, L; cin >> N >> L;
    long long count = (N + L - 1) / L;
    count%=mod;
    long long ans = 1;
    vector<long long>A(32);
    A[0] = 2;
    for (long long i = 1; i < 32; i++) {
        A[i] = A[i - 1] * A[i - 1];
        A[i] %= mod;
    }
    for (long long i = 0; i < 32; i++) {
        if (count & (1 << i)) {
            ans *= A[i]; ans %= mod;
        }
    }
    ans--;
    cout << ans << endl;
}