#line 1 "a.cpp" #include using namespace std; #line 3 "/home/kotatsugame/library/math/modint.cpp" #include template struct modint{ unsigned int x; constexpr modint()noexcept:x(){} template constexpr modint(T x_)noexcept:x((x_%=m)<0?x_+m:x_){} constexpr unsigned int val()const noexcept{return x;} constexpr modint&operator++()noexcept{if(++x==m)x=0;return*this;} constexpr modint&operator--()noexcept{if(x==0)x=m;--x;return*this;} constexpr modint operator++(int)noexcept{modint res=*this;++*this;return res;} constexpr modint operator--(int)noexcept{modint res=*this;--*this;return res;} constexpr modint&operator+=(const modint&a)noexcept{x+=a.x;if(x>=m)x-=m;return*this;} constexpr modint&operator-=(const modint&a)noexcept{if(x>=1)if(n&1)r*=x; return r; } constexpr modint inv()const noexcept { int s=x,t=m,x=1,u=0; while(t) { int k=s/t; s-=k*t; swap(s,t); x-=k*u; swap(x,u); } return modint(x); } friend constexpr modint operator+(const modint&a,const modint&b){return modint(a)+=b;} friend constexpr modint operator-(const modint&a,const modint&b){return modint(a)-=b;} friend constexpr modint operator*(const modint&a,const modint&b){return modint(a)*=b;} friend constexpr modint operator/(const modint&a,const modint&b){return modint(a)/=b;} friend constexpr bool operator==(const modint&a,const modint&b){return a.x==b.x;} friend constexpr bool operator!=(const modint&a,const modint&b){return a.x!=b.x;} friend ostream&operator<<(ostream&os,const modint&a){return os<>(istream&is,modint&a){long long v;is>>v;a=modint(v);return is;} }; #line 4 "a.cpp" using mint=modint<998244353>; int N; mint fac[1<<20],inv[1<<20]; mint C(int a,int b){return fac[a]*inv[b]*inv[a-b];} main() { cin>>N; fac[0]=1; for(int i=1;i<=N;i++)fac[i]=fac[i-1]*i; inv[N]=1/fac[N]; for(int i=N;i--;)inv[i]=inv[i+1]*(i+1); mint ans=fac[N]*N; for(int i=0;i=1)ans-=C(N-2,i-1)*fac[i]*2*t; if(N-3>=i)ans+=C(N-3,i)*fac[i]*(N-2)*t; if(i>=2)ans-=C(N-3,i-2)*fac[i]*(N-2)*t; } cout<