#include using namespace std; #define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++) #define ALL(v) (v).begin(),(v).end() using ll=long long int; const int inf = 0x3fffffff; const ll INF = 0x1fffffffffffffff; const double eps=1e-12; templateinline bool chmax(T& a,T b){if(ainline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;} templatestruct fp { int v; static int get_mod(){return mod;} int inv() const{ int tmp,a=v,b=mod,x=1,y=0; while(b)tmp=a/b,a-=tmp*b,swap(a,b),x-=tmp*y,swap(x,y); if(x<0){x+=mod;} return x; } fp(ll x=0){init(x%mod+mod);} fp& init(int x){v=(x>=1;} return res;} fp& operator+=(const fp& x){return init(v+x.v);} fp& operator-=(const fp& x){return init(v+mod-x.v);} fp& operator*=(const fp& x){v=ll(v)*x.v%mod; return *this;} fp& operator/=(const fp& x){v=ll(v)*x.inv()%mod; return *this;} fp operator+(const fp& x)const{return fp(*this)+=x;} fp operator-(const fp& x)const{return fp(*this)-=x;} fp operator*(const fp& x)const{return fp(*this)*=x;} fp operator/(const fp& x)const{return fp(*this)/=x;} bool operator==(const fp& x)const{return v==x.v;} bool operator!=(const fp& x)const{return v!=x.v;} }; using Fp=fp<>; templatestruct factorial { vector Fact,Finv,Inv; factorial(int maxx){ Fact.resize(maxx); Finv.resize(maxx); Inv.resize(maxx); Fact[0]=Fact[1]=Finv[0]=Finv[1]=Inv[1]=1; rep(i,2,maxx){Fact[i]=Fact[i-1]*i;} Finv[maxx-1]=Fact[maxx-1].inv(); for(int i=maxx-1;i>=2;i--){Finv[i-1]=Finv[i]*i; Inv[i]=Finv[i]*Fact[i-1];} } T fact(int n,bool inv=0){if(n<0)return 0; return (inv?Finv[n]:Fact[n]);} T inv(int n){if(n<0)return 0; return Inv[n];} T nPr(int n,int r,bool inv=0){if(n<0||n>n; vector a(n); rep(i,0,n)cin>>a[i]; dp[0][0]=1; rep(i,0,n){ if(a[i]==-1){ if(nCr(n-1,i)){ rep(j,0,2)dp[i+1][j]+=dp[i][j]*2; } else{ Fp add=dp[i][0]+dp[i][1]; dp[i+1][0]+=add; dp[i+1][1]+=add; } } else{ if(nCr(n-1,i)){ rep(j,0,2)dp[i+1][j]+=dp[i][j]; } else{ dp[i+1][0]+=dp[i][a[i]]; dp[i+1][1]+=dp[i][a[i]^1]; } } } cout<