import std.stdio: readf, writeln;

const MOD = 998244353;

void main() {
    int n, k;
    readf("%d %d\n", n, k);
    auto dp = new int[n + 1];
    dp[0] = 1;
    foreach(i; 0..n) {
        if(i + k <= n) {
            dp[i + k] += dp[i];
            dp[i + k] %= MOD;
        }
        dp[i + 1] += dp[i];
        dp[i + 1] %= MOD;
    }
    writeln(dp[n]);
}