#line 1 "a.cpp" #include #include #include #include using namespace std; #line 2 "/home/kotatsugame/library/math/modint.cpp" #include #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 7 "a.cpp" using mint=modint<(int)1e9+7>; int N; int A[2<<17]; mint rec(int L,int R) { int sum=(R-L)*2; long prod=1; for(int i=L;i=sum)prod=sum; } if(prod>=sum) { mint ret=1; for(int i=L;i > >B; for(int i=L;i>i&1) { if(now<0)now=1; if(B[i+1].first>0)now*=B[i+1].first; } else { sum+=abs(now); now=B[i+1].first; } } sum+=abs(now); if(ans>i&1) { if(now<0)now=1; if(B[i+1].first>0)now*=B[i+1].first; } else { ret+=abs(now); now=B[i+1].first; } } ret+=abs(now); return ret; } mint func(int L,int R) { mint ret=0; while(L