#include using namespace std; using ll=long long; using pii=pair; #define all(a) a.begin(),a.end() #define pb push_back #define sz(a) ((int)a.size()) const int N=500005,mod=998244353; int add(int x, int y){x+=y; if(x>=mod) x-=mod; return x;} int sub(int x, int y){x-=y; if(x<0) x+=mod; return x;} int mul(int x, int y){return ((ll)x)*y%mod;} int n,fac[N],inv[N],ifac[N]; void amano_hina_is_the_goat(){ fac[0]=inv[1]=ifac[0]=1; for(int i=1; i> n; int res=0; for(int i=0; i*2<=n; ++i) res=add(res,mul(mul(fac[n],ifac[n-i*2]),mul(ifac[i],ifac[i]))); res=mul(sub(res,1),(mod+1)/2); cout << res << "\n"; } signed main(){ ios_base::sync_with_stdio(0),cin.tie(0); cout << fixed << setprecision(20); int t=1; //cin >> t; while(t--) amano_hina_is_the_goat(); }