#include "bits/stdc++.h"
using namespace std;

int main() {
	int N;
	long long ans = 1, count = 0, A, MOD = 1000000007;
	vector<pair<long long, int> > V;
	cin >> N;
	for (int i = 0; i < N * 2; i++) {
		cin >> A;
		if (i < N) V.push_back({ A, 1 });
		else V.push_back({ A, -1 });
	}
	sort(V.begin(), V.end());
	for (auto it = V.begin(); it != V.end(); it++) {
		if ((count < 0 && it->second > 0) || (count > 0 && it->second < 0)) {
			ans *= abs(count);
			ans = ans % MOD;
		}
		count += it->second;
	}
	cout << ans;
}