#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
const int N = 1e5 + 10;
double a[N], b[N];
int main(int argc, char const *argv[]) {
int n; cin >> n;
for(int i = 1; i <= n; i++) cin >> a[i];
for(int i = 1; i <= n; i++) cin >> b[i];
sort(a + 1, a + n + 1, greater<double>());
sort(b + 1, b + n + 1, greater<double>());
for(int i = 1; i <= n; i++)
a[i] += a[i - 1], b[i] += b[i - 1];
double ans = 0;
for(int i = 0; i <= n; i++) {
for(int j = 0; j <= n; j++) {
ans = max(ans, min(a[i], b[j]) - i - j);
}
}
cout << fixed << setprecision(4) << ans << endl;
}
