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

float fac(int n){
    if(n<2) return 1;
    return n*fac(n-1);
}

int main(){
    cin.tie(0); ios::sync_with_stdio(false);
   
    int n; cin>>n; int a[n],b[n];
    for (int i = 0; i < n; i++)cin>>a[i];
    for (int i = 0; i < n; i++)cin>>b[i];
    float ans=0; sort(a,a+n); sort(b,b+n);
    do{
        do{
            int ac=0,bc=0;
            for (int i = 0; i < n; i++){
                if(a[i]>b[i])ac++;
                else bc++;
            }
            if(ac>bc)ans++;
        }while(next_permutation(b,b+n));
        sort(b,b+n);
    }while(next_permutation(a,a+n));
    cout<<ans/(fac(n)*fac(n))<<'\n';
}