#include <bits/stdc++.h>
using namespace std;
const int N = 8e6 + 9;
const int mod = 1e9 + 7;
int extended_euclidean(int a, int b, int& x, int& y) {
if (b == 0) {
x = 1;
y = 0;
return a;
}
int x1, y1;
int d = extended_euclidean(b, a % b, x1, y1);
x = y1;
y = x1 - y1 * (a / b);
return d;
}
std::vector<int> invs(const std::vector<int> &a, int m) {
int n = a.size();
if (n == 0) return {};
std::vector<int> b(n);
int v = 1;
for (int i = 0; i != n; ++i) {
b[i] = v;
v = static_cast<long long>(v) * a[i] % m;
}
int x, y;
extended_euclidean(v, m, x, y);
x = (x % m + m) % m;
for (int i = n - 1; i >= 0; --i) {
b[i] = static_cast<long long>(x) * b[i] % m;
x = static_cast<long long>(x) * a[i] % m;
}
return b;
}
long long fact[N];
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
int n;
cin >> n;
int a[n] , b[n];
fact[0] = fact[1] = 1;
for(int i = 2; i < N; i++){
fact[i] = fact[i - 1] * i;
fact[i] %= mod;
}
for(int i = 0; i < n; i++) cin >> a[i];
for(int i = 0; i < n; i++) cin >> b[i];
vector<int> arr(n);
long long sum = 0;
int test= 1;
for(int i = 0; i < n; i++){
int e =(b[i] - a[i]) / ( i + 1 );
if(e < 0) test = 0;
if((b[i] - a[i]) % ( i + 1 )) test = 0;
sum += e;
arr[i] = fact[e];
}
if(test == 0){
cout << 0 << "\n";
return 0;
}
long long ans = fact[sum];
vector<int> v = invs(arr, mod);
for(int i = 0; i < n; i++){
ans *= v[i];
ans %= mod;
}
cout << ans << "\n";
return 0;
}
Copy