#include<bits/stdc++.h>
#define Gc() getchar()
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define eb emplace_back
#define all(x) x.begin(),x.end()
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;
const int N=20+5,M=N*4+5,K=1000+5,mod=1e9+7,Mod=mod-1;const db eps=1e-9;const ll INF=1e18+7;mt19937 rnd(time(0));
#define Tp template<typename T>
#define Ts template<typename T,typename... Ar>
namespace Debug{
	Tp void _debug(char* f,T t){cerr<<f<<'='<<t<<endl;}
	Ts void _debug(char* f,T x,Ar... y){while(*f!=',') cerr<<*f++;cerr<<'='<<x<<",";_debug(f+1,y...);}
	#ifdef LOCAL
	#define gdb(...) _debug((char*)#__VA_ARGS__,__VA_ARGS__)
	#else 
	#define gdb(...) void()
	#endif
}using namespace Debug;
int n,A[N],B[N];
ll C[N][N],iv[N];
int Ch[N];
ll mpow(ll x,int y=mod-2){ll ans=1;while(y) y&1&&(ans=ans*x%mod),y>>=1,x=x*x%mod;return ans;}
ll ans=0;
void dfs(int x,int y){
	if(!x){
		if(__builtin_popcount(y)<2) return;
		ll mul=1;for(int i=1;i<=Ch[1];i++) mul=mul*C[1][i]%mod;
		mul=mpow(mul);
		mul=mul*(A[__lg(y)+1]-A[__lg(y&-y)+1]+mod)%mod;
		for(int i=__lg(y&-y)+1+1;i<=__lg(y);i++) if(y>>i-1&1) mul=mul*A[i]%mod;
		// gdb(mul);
		mul=mul*mpow(2*(iv[__lg(y&-y)+1]-iv[__lg(y)+1]+mod)%mod)%mod;
		// gdb(mul,y);
		ans+=B[__builtin_popcount(y)]*mpow(mul)%mod;
		return;
	}
	Ch[x]=Ch[x+1];Mc(C[x],C[x+1]);
	dfs(x-1,y);
	if(!y){
		dfs(x-1,y|(1<<x-1));
	}else{
		if(__builtin_popcount(y)^1) C[x][++Ch[x]]=A[x];
		else C[x][++Ch[x]]=A[__lg(y)+1]-A[x];
		static ll D[N];int Dh=0;
		D[Dh=1]=A[__lg(y)+1]-A[x];for(int i=x+1;i<=__lg(y);i++) if(y>>i-1&1) D[++Dh]=A[i];
		for(int i=1;i<=Ch[x];i++){
			ll p=C[x][i];
			for(int j=1;j<=Dh;j++){
				ll w=__gcd(p,D[j]);
				p/=w;D[j]/=w;
			}
			C[x][i]/=p;
		}
		dfs(x-1,y|(1<<x-1));
	}
}
void Solve(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&A[i]),iv[i]=mpow(A[i]);
	for(int i=2;i<=n;i++) scanf("%d",&B[i]);
	for(int i=0;i<=n;i++) for(int j=C[i][0]=1;j<=i;j++) C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
	for(int i=2;i<=n;i++) for(int j=2;j<i;j++) B[i]=(B[i]+(mod-B[j])*C[i][j])%mod;
	dfs(n,0);
	printf("%lld\n",ans%mod);
}
int main(){
	int t=1;
	// scanf("%d",&t);
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}