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#include
     
      using namespace std;typedef long long LL;//=========================================================namespace IO {      const int MX = 4e7; //1e7占用内存11000kb      char buf[MX]; int c, sz;      void begin() {          c = 0;          sz = fread(buf, 1, MX, stdin);      }      inline bool read(int &t) {          while(c < sz && buf[c] != '-' && (buf[c] < '0' || buf[c] > '9')) c++;          if(c >= sz) return false;          bool flag = 0; if(buf[c] == '-') flag = 1, c++;          for(t = 0; c < sz && '0' <= buf[c] && buf[c] <= '9'; c++) t = t * 10 + buf[c] - '0';          if(flag) t = -t;          return true;      }  }//=========================================================const LL mod=1e9+7;const LL M=1e6+5;LL fac[M+5];                //阶乘    LL inv_of_fac[M+5];        //阶乘的逆元 LL qpow(LL x,LL n){    LL ret=1;    for(; n; n>>=1)    {        if(n&1) ret=ret*x%mod;        x=x*x%mod;    }    return ret;}void init(){    fac[0]=1;    for(int i=1; i<=M; i++)        fac[i]=fac[i-1]*i%mod;    inv_of_fac[M]=qpow(fac[M],mod-2);    for(int i=M-1; i>=0; i--)        inv_of_fac[i]=inv_of_fac[i+1]*(i+1)%mod;}LL C(LL a,LL b){    if(b<0||a
      
       rhs.r;    }}a[M];int mark,rear,n;LL dfs(int l,int r){    if(mark) return 0;    if(l>r) return 1;    if(a[rear].l!=l||a[rear].r!=r)    {        mark=1;        return 0;    }    node cur=a[rear++];    LL ret=C(cur.r-cur.l,cur.id-cur.l);    ret=ret*dfs(cur.l,cur.id-1)%mod;    ret=ret*dfs(cur.id+1,cur.r)%mod;    return ret; }int main(){    init();    int kase=0;    IO::begin();    while(IO::read(n))    {        for(int i=1;i<=n;i++)    IO::read(a[i].l);        for(int i=1;i<=n;i++)    IO::read(a[i].r),a[i].id=i;        sort(a+1,a+1+n);        mark=0,rear=1;        printf("Case #%d: %lld\n", ++kase, dfs(1, n));     }}