#include <iostream>
#include <vector>

using namespace std;
typedef long long ll;

constexpr ll MOD = 998244353;

ll calc_pow(ll x, ll pow) {
    if (pow == 0) return 1;
    ll a = calc_pow(x, pow / 2);
    a = a * a % MOD;
    if (pow % 2 == 1) a *= x;
    return a % MOD;
}

int main() {
    ll n, l;
    cin >> n >> l;
    ll x = (n + l - 1) / l;
    cout << (calc_pow(2, x) + MOD - 1) % MOD << endl;
    return 0;
}