#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long N = 2e5 + 10;
long long n;
long long m[N], a[N];
long long qpl[N];
long long dx = 0;
void dfs(long long pos) {
	if (pos == n + 1) {
		//if (check()) {
			//for (long long i = 1; i <= n; i++) {
			//	cout << qpl[i] << " ";
			//}
			//cout<<endl; 
			dx++;
			dx%=mod;

		//}
		//cout << endl;
	}
	for (long long i = 1; i <= m[pos]; i++) {
		qpl[pos] = i;
		long long k = abs(qpl[1] - a[1]);
		if (abs(qpl[pos] - a[pos]) == k) 
		    dfs(pos + 1);
	}
}

int main() {
	cin >> n;

	for (long long i = 1; i <= n; i++) {
		cin >> m[i];
		//dx = (dx * m[i]) % mod;
	}
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	dfs(1);
	cout << (dx) % mod;
	return 0;
}

该怎么剪支，已经感觉优化不了了