#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
long long RepeatSquaring(long long N, long long P, long long M) {
    if (P == 0) return 1;
    if (P % 2 == 0) {
        long long t = RepeatSquaring(N, P / 2, M);
        return t * t % M;
    }
    return N * RepeatSquaring(N, P - 1, M)%M;
}
signed main() {
    long long N, L; cin >> N >> L;
    long long count = (N + L - 1) / L;
    cout<<RepeatSquaring(2,count,mod)-1<<endl;
}