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

int main() {
	srand(time(NULL));

	int n;
	cin >> n;

	vector<int> a(n);
	vector<int> b(n);
	for (int i = 0; i < n; i++) {
		scanf("%d", &a[i]);
	}
	for (int i = 0; i < n; i++) {
		scanf("%d", &b[i]);
	}
	int cnt = 0;
	for (int ii = 0; ii < 1234567; ii++) {
		random_shuffle(a.begin(), a.end());
		random_shuffle(b.begin(), b.end());
		int win = 0;
		for (int i = 0; i < n; i++) {
			if (a[i] > b[i]) win++;
			if (a[i] < b[i]) win--;
		}
		cnt += win > 0;
	}
	
	printf("%.20f\n", cnt / 1234567.0);
}