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

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N;
    cin >> N;

    vector<ll> A(N);
    FOR(i, 0, N){
        cin >> A.at(i);
    }

    vector<ll> B(N);
    FOR(i, 0, N){
        cin >> B.at(i);
    }

    std::random_device seed_gen;
    std::mt19937 engine(seed_gen());
    ll count = 0;
    FOR(i, 0, 500000){
        shuffle(ALL(A), engine);
        shuffle(ALL(B), engine);
        
        ll a_win = 0;
        ll b_win = 0;

        FOR(j, 0, N){
            if(A[j]>B[j]){
                a_win++;
            }else{
                b_win++;
            }
        }
        if(a_win > b_win){
            count++;
        }
    }

    cout << setprecision(20);
    p(count / 500000.0);

    return 0;
}