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

typedef long long ll;
typedef modint998244353 mint;
const int MOD = 998244353;
#define all(x) x.begin(), x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const int dx[8] = {1, 0, -1, 0, -1, -1, 1, 1};
const int dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
template <class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template <class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

//iの階乗の逆元
vector<mint> fact_inv;
//iの逆元
vector<mint> inv;

//前処理
void init_nCk(int k){
    fact_inv.resize(k + 5);
    inv.resize(k + 5);

    //初期化
    fact_inv[0] = fact_inv[1] = 1;
    inv[1] = 1;

    for(int i = 2; i < k + 5; i++){
        inv[i] = MOD - inv[MOD % i] * (MOD / i);
        fact_inv[i] = fact_inv[i - 1] * inv[i];
    }
}

mint nCk(ll n, ll k){
    mint ans = 1;
    for(ll i = n; i >= n - k + 1; i--){
        ans *= i;
    }
    return ans * fact_inv[k];
}

mint modpow(ll a, ll n){
    mint res = 1;
    while(n > 0){
        if(n & 1) res = res * a;
        a = a * a;
        n >>= 1;
    }
    return res;
}

int main(){
    ll n, m;
    cin >> n >> m;

    if(n < m){
        cout << 0 << endl;
        return 0;
    }

    mint ans = modpow(2, n);
    init_nCk(100000);
    rep(i, m){
        ans -= modpow(2, i) * nCk(n, i);
    }

    //ans--;
    cout << ans.val() << endl;

    return 0;
}