#include using namespace std; using ll=long long; using ull=unsigned long long; using P=pair; templateusing minque=priority_queue,greater>; templatebool chmax(T &a,const T &b){return (abool chmin(T &a,const T &b){return (a>b?(a=b,true):false);} templateistream &operator>>(istream &is,pair&p){is>>p.first>>p.second;return is;} templateistream &operator>>(istream &is,tuple&a){is>>std::get<0>(a)>>std::get<1>(a)>>std::get<2>(a);return is;} templateistream &operator>>(istream &is,array&a){for(auto&i:a)is>>i;return is;} templateistream &operator>>(istream &is,vector &a){for(auto &i:a)is>>i;return is;} templatevoid operator++(pair&a,int n){a.first++,a.second++;} templatevoid operator--(pair&a,int n){a.first--,a.second--;} templatevoid operator++(vector&a,int n){for(auto &i:a)i++;} templatevoid operator--(vector&a,int n){for(auto &i:a)i--;} #define overload3(_1,_2,_3,name,...) name #define rep1(i,n) for(int i=0;i<(int)(n);i++) #define rep2(i,l,r) for(int i=(int)(l);i<(int)(r);i++) #define rep(...) overload3(__VA_ARGS__,rep2,rep1)(__VA_ARGS__) #define reps(i,l,r) rep2(i,l,r) #define all(x) x.begin(),x.end() #define pcnt(x) __builtin_popcountll(x) #define fin(x) return cout<<(x)<<'\n',static_cast(0) #define yn(x) cout<<((x)?"Yes\n":"No\n") #define uniq(x) sort(all(x)),x.erase(unique(all(x)),x.end()) template inline int fkey(vector&z,T key){return lower_bound(z.begin(),z.end(),key)-z.begin();} ll myceil(ll a,ll b){return (a+b-1)/b;} template auto vec(const int (&d)[n],const T &init=T()){ if constexpr (id(d,init)); else return init; } #ifdef LOCAL #include #define SWITCH(a,b) (a) #else #define debug(...) static_cast(0) #define debugg(...) static_cast(0) #define SWITCH(a,b) (b) templateostream &operator<<(ostream &os,const pair&p){os<>testcase; for(int i=0;i #include templateconstexpr std::enable_if_t,T> epsilon(){return 1e-10;} templateconstexpr std::enable_if_t,T>epsilon(){return 0;} template struct Point3d{ static_assert(std::is_arithmetic_v); static constexpr T eps=epsilon(); static constexpr T T_abs(T x){return xx+=rhs.x; this->y+=rhs.y; this->z+=rhs.z; return *this; } Point3d &operator-=(const Point3d&rhs){ this->x-=rhs.x; this->y-=rhs.y; this->z-=rhs.z; return *this; } Point3d &operator*=(const T&rhs){ this->x*=rhs; this->y*=rhs; this->z*=rhs; return *this; } Point3d &operator/=(const T&rhs){ this->x/=rhs; this->y/=rhs; this->z/=rhs; return *this; } friend Point3d operator+(const Point3d&lhs,const Point3d&rhs){return Point3d(lhs)+=rhs;} friend Point3d operator-(const Point3d&lhs,const Point3d&rhs){return Point3d(lhs)-=rhs;} friend Point3d operator*(const Point3d&lhs,const T&rhs){return Point3d(lhs)*=rhs;} friend Point3d operator/(const Point3d&lhs,const T&rhs){return Point3d(lhs)/=rhs;} friend bool operator==(const Point3d&lhs,const Point3d&rhs){return T_abs(lhs.x-rhs.x)<=eps&&T_abs(lhs.y-rhs.y)<=eps&&T_abs(lhs.z-rhs.z)<=eps;} friend bool operator!=(const Point3d&lhs,const Point3d&rhs){return !(lhs==rhs);} friend std::istream &operator>>(std::istream&is,Point3d&p){ is>>p.x>>p.y>>p.z; return is; } friend std::ostream &operator<<(std::ostream&os,const Point3d&p){ os< Point3dconvert()const{ Point3dres(this->x,this->y,this->z); return res; } }; template Point3d cross(const Point3d&a,const Point3d&b){return Point3d(a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x);} template T dot(const Point3d&a,const Point3d&b){return a.x*b.x+a.y*b.y+a.z*b.z;} constexpr int carmichael_constexpr(int n){ if(n==998244353)return 998244352; if(n==1000000007)return 1000000006; if(n<=1)return n; int res=1; int t=0; while(n%2==0){ n/=2; t++; } if(t==2)res=2; else if(t>=3)res=1<<(t-2); for(int i=3;i*i<=n;i++)if(n%i==0){ int c=0; while(n%i==0){ n/=i; c++; } int prod=i-1; for(int j=0;j struct mod_int{ private: static constexpr unsigned int umod=static_cast(m); static constexpr unsigned int car=carmichael_constexpr(m); using uint=unsigned int; using mint=mod_int; uint v; static_assert(mval()<=1)return *this; if constexpr(m%8==1){ mint b=2; while(b.pow((m-1)/2).val()==1)b++; int m2=m-1,e=0; while(m2%2==0)m2>>=1,e++; mint x=this->pow((m2-1)/2); mint y=(*this)*x*x; x*=*this; mint z=b.pow(m2); while(y.val()!=1){ int j=0; mint t=y; while(t.val()!=1)t*=t,j++; z=z.pow(1<<(e-j-1)); x*=z; z*=z; y*=z;e=j; } return x; } else if constexpr(m%8==5){ mint ret=this->pow((m+3)/8); if((ret*ret).val()==this->val())return ret; else return ret*mint::raw(2).pow((m-1)/4); } else{ return this->pow((m+1)/4); } } public: using value_type=uint; mod_int():v(0){} template,std::nullptr_t> =nullptr> mod_int(T a){ a%=m; if(a<0)v=a+umod; else v=a; } template,std::nullptr_t> =nullptr> mod_int(T a):v(a%umod){} static constexpr mint raw(int a){ mint ret; ret.v=a; return ret; } inline uint val()const{return this->v;} static constexpr int mod(){return m;} inline mint &operator+=(const mint &b){ this->v+=b.v; if(this->v>=umod)this->v-=umod; return *this; } inline mint &operator-=(const mint &b){ this->v-=b.v; if(this->v>=umod)this->v+=umod; return *this; } inline mint &operator*=(const mint &b){ this->v=((unsigned long long)this->v*b.v)%umod; return *this; } inline mint &operator/=(const mint &b){ *this*=b.inv(); return *this; } inline mint operator+()const{return *this;} inline mint operator-()const{return mint()-*this;} friend inline mint operator+(const mint &a,const mint &b){return mint(a)+=b;} friend inline mint operator-(const mint &a,const mint &b){return mint(a)-=b;} friend inline mint operator*(const mint &a,const mint &b){return mint(a)*=b;} friend inline mint operator/(const mint &a,const mint &b){return mint(a)/=b;} friend inline bool operator==(const mint &a,const mint &b){return a.val()==b.val();} friend inline bool operator!=(const mint &a,const mint &b){return !(a==b);} friend inline bool operator<(const mint &a,const mint &b){return a.val()(const mint &a,const mint &b){return a.val()>b.val();} friend inline bool operator<=(const mint &a,const mint &b){return a.val()<=b.val();} friend inline bool operator>=(const mint &a,const mint &b){return a.val()>=b.val();} inline mint operator++(int){ mint ret=*this; *this+=mint::raw(1); return ret; } inline mint operator--(int){ mint ret=*this; *this-=mint::raw(1); return ret; } mint pow(long long n)const{ mint ret=mint::raw(1),a(*this); while(n){ if(n&1)ret*=a; a*=a; n>>=1; } return ret; } inline mint inv()const{ assert(this->v!=0); return pow(car-1); } std::optionalsqrt()const{ if(this->val()<=1||this->pow((m-1)/2)==1)return std::make_optional(this->sqrt_impl()); else return std::nullopt; } static constexpr unsigned int order(){return car;} friend std::istream &operator>>(std::istream &is,mint &b){ long long a; is>>a; b=mint(a); return is; } friend std::ostream &operator<<(std::ostream &os,const mint &b){ os< struct std::hash>{ std::size_t operator()(mod_intx)const{ return std::hash()(x.val()); } }; using mint998=mod_int<998244353>; using mint107=mod_int<1000000007>; using mint=mint998; paircalc(Point3da,Point3dl){ ll diff=l.z-a.z; mint coef=mint(l.z)/mint(diff); return {l.x-(a.x-l.x)*coef,l.y-(a.y-l.y)*coef}; } void SOLVE(){ static mint inv2=mint(2).inv(); Point3da,b,c,l; cin>>a>>b>>c>>l; if(dot(l-a,cross(b-a,c-a))<0)swap(b,c); auto ma=calc(a,l),mb=calc(b,l),mc=calc(c,l); mb.first-=ma.first; mc.first-=ma.first; mb.second-=ma.second; mc.second-=ma.second; cout<<(mb.first*mc.second-mc.first*mb.second)*inv2<<'\n'; }