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

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
    for(T& x : vec) is >> x;
    return is;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<pair<int,int>> a(n), b(n);
    ll X0 = 0, Y0 = 0, X1 = 0, Y1 = 0;
    ll sx0 = 0, sy0 = 0, sx1 = 0, sy1 = 0;
    for(auto &&[x, y] : a){
        cin >> x >> y;
        X0 += x, Y0 += y;
    }
    for(auto &&[x, y] : b){
        cin >> x >> y;
        X1 += x, Y1 += y;
    }
    double GX0 = double(X0) / n, GY0 = double(Y0) / n;
    double GX1 = double(X1) / n, GY1 = double(Y1) / n;
    double s0 = 0, s1 = 0;
    for(auto &&[x, y] : a){
        double dx = x - GX0;
        double dy = y - GY0;
        s0 += sqrtl(dx * dx + dy * dy);
    }
    for(auto &&[x, y] : b){
        double dx = x - GX1;
        double dy = y - GY1;
        s1 += sqrtl(dx * dx + dy * dy);
    }
    cout << fixed << setprecision(15) << s1 / s0 << '\n';
}