#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;

typedef long long LL;

const int N = 3005, P = 1e9 + 7;

int n, s[N], t[N], f[N][N], g[N][N], ans, fact[N];

void inline add(int &a, int b) {
	(a += b) %= P;
}

int main() {
	scanf("%d", &n);
	fact[0] = 1;
	for (int i = 1; i <= n; i++) scanf("%d", s + i), fact[i] = (LL)fact[i - 1] * i % P;
	for (int i = 1; i <= n; i++) scanf("%d", t + i);
	sort(s + 1, s + 1 + n);
	sort(t + 1, t + 1 + n);
	f[0][0] = 1;
	for (int i = 1, j = 0; i <= n; i++) {
		while (j < n && s[j + 1] <= t[i]) ++j;
		for (int k = 0; k <= i; k++) {
			if (!f[i - 1][k]) continue;
			(f[i][k] += f[i - 1][k]) %= P;
			if (j - k > 0) add(f[i][k + 1], (LL)f[i - 1][k] * (j - k) % P);
		}
	}
	g[n + 1][0] = 1;
	for (int i = n, j = n; i; i--) {
		while (j && t[j] >= s[i]) j--;
		for (int k = 0; k <= n - i; k++) {
			if (!g[i + 1][k]) continue;
			(g[i][k] += g[i + 1][k]) %= P;
			if (n - j - k > 0) add(g[i][k + 1], (LL)g[i + 1][k] * (n - j - k) % P);
		}
	}

	ans = f[n][n];
	
	for (int i = n, j = n; i; i--) {
		while (j && t[j] >= s[i]) j--;
		int t = n - j; 
		for (int k = 0; k <= min(i - 1, t); k++) {
			add(ans, (LL)f[j][i - 1 - k] * fact[k] % P * g[i + 1][t - k] % P);
		}
	}
	printf("%d\n", ans);
	return 0;
}