public static void main(String[] args) { Scanner scanner = new Scanner(new BufferedReader(new InputStreamReader(System.in))); int n = scanner.nextInt(); int[] count = new int[n], capacity = new int[n]; for (int i = 0; i < n; i++) { count[i] = scanner.nextInt(); } for (int i = 0; i < n; i++) { capacity[i] = scanner.nextInt(); } Arrays.sort(count); Arrays.sort(capacity); long res = 1; int right = n - 1; for (int i = n - 1; i >= 0; i--) { while (right >= 0 && capacity[right] >= count[i]) right--; res *= (n - 1 - right) - (n - 1 - i); res %= 100000007; if (res == 0) break; } System.out.println(res); }