#include <bits/stdc++.h>
using namespace std;

#ifdef _RUTHEN
#include <debug.hpp>
#else
#define show(...) true
#endif

using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
template <class T> using V = vector<T>;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll N, M;
    cin >> N >> M;
    mint ans = mint(2).pow(N), b = 1;
    ;
    rep(i, M) {
        // ans -= binom(N, i);
        ans -= b;
        b = b * (N - i) / mint(i + 1);
        show(b.val());
    }
    cout << ans.val() << '\n';
    return 0;
}