#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
	int n, i, j, used = 0, out = 1;
	cin >> n;

	vector<int> a(n);
	vector<int> b(n);

	for (i = 0; i < n; i++)
	{
		cin >> a[i];
	}
	for (i = 0; i < n; i++)
	{
		cin >> b[i];
	}

	sort(a.begin(), a.end());
	sort(b.begin(), b.end());

	for (i = 0; i < n; i++)
	{
		j = used;
		while (j < n && b[j] <= a[i])
		{
			j++;
		}

		out *= j - used;
		used++;
	}

	cout << out;
}