#include <iostream>
#include <random>
#include <vector>

constexpr int battleNum = 100000;

int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    
    std::random_device rnd;
    std::mt19937 mt(rnd());
    
    int n;
    std::cin >> n;
    std::vector<int> a(n), b(n);
    for(auto& it : a){
        std::cin >> it;
    }
    for(auto& it : b){
        std::cin >> it;
    }
    int cnt=0;
    for(int i=0; i<battleNum; ++i){
        int winCnt=0;
        std::vector<int> tmpA(a), tmpB(b);
        for(int j=n; j>=1; --j){
            int tmpAN = mt()%j;
            int tmpBN = mt()%j;
            if(tmpA[tmpAN]>tmpB[tmpBN]) ++winCnt;
            if(tmpA[tmpAN]<tmpB[tmpBN]) --winCnt;
            tmpA.erase(tmpA.begin()+tmpAN);
            tmpB.erase(tmpB.begin()+tmpBN);
        }
        if(winCnt>0) ++cnt;
    }
    std::cout << 1.0*cnt/battleNum << "\n";
    return 0;
}