#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll ILL=1167167167167167167; const int INF=2100000000; const ll mod=998244353; #define rep(i,a) for (int i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} ll jyo(ll x,ll y,ll z){ ll H=y; //ここから ll a=1,b=x,c=1; while(H>0){ a*=2; if(H%a!=0){ H-=a/2; c*=b; c%=z; } b*=b; b%=z; } //ここまで return c; } void solve(); // rainy ~ 雨に打たれて ~ int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t=1; //cin>>t; rep(i,t) solve(); } void solve(){ ll n,k; cin>>n>>k; ll ans=0; ll tmp=1; for(int i=k-1;i>0;i--){ tmp*=(i+1); tmp%=mod; tmp*=jyo(k-i,mod-2,mod); tmp%=mod; ll val=(tmp*jyo(i,n,mod)); val%=mod; val*=jyo(-2,k-1-i,mod); val%=mod; ans+=val; //cout<