#include <iostream>
#include <iomanip>
#include <complex>
#include <vector>
#include <cmath>
#define EPS 1e-8
using namespace std;
typedef complex<double> P;

int main(){
    int n;
    cin >> n;

    vector<P> G(n);
    for(int i=0; i<n; i++){
        int x,y;
        cin >> x >> y;
        G[i] = P(x,y);
    }

    if(n%2!=0){
        cout << "NA" << endl;
        return 0;
    }

    int half = G.size()/2;
    P mid = (G[0] + G[half])/P(2,0);
    for(int i=1; i<half; i++){
        P tmpmid = (G[i] + G[i+half])/P(2,0);
        if(fabs(real(tmpmid)-real(mid))>EPS ||
           fabs(imag(tmpmid)-imag(mid))>EPS){
            cout << "NA" << endl;
            return 0;
        }
    }
    cout << fixed;
    cout << setprecision(5);
    cout << real(mid) << " " << imag(mid) << endl;
            
    return 0;
}