#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

ll pow_mod(ll x, ll n, ll mod){
    ll ret = 1;
    while(n > 0){
        if(n & 1) ret = (ret*x)%mod;
        x = x*x%mod;
        n >>=1;
    }
    return ret;
}

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

    if(n < m){
        cout << 0 << endl;
    }else{
        ll ans = pow_mod(2, n, MOD);
        
        vector<ll> dp(m);
        dp[0] = 1;
        for(ll i=1; i<m; i++){
            dp[i] = (dp[i-1] * ((n-i+1)%MOD))%MOD;
            dp[i] = (dp[i] * pow_mod(i, MOD-2, MOD))%MOD;
        }

        rep(i, m){
            ans = (ans - dp[i] + MOD)%MOD;
        }

        cout << ans << endl;
    }
}