#include<iostream>
#include<cmath>
#include<cstdio>
#define EPS (1e-7)
#define N 50
using namespace std;
int n,x[N],y[N],flag=1;
double gx,gy;

int main(){
  cin>>n;
  if(n%2)flag=0;
  for(int i=0;i<n;i++){
    cin>>x[i]>>y[i];
    gx+=x[i]; gy+=y[i];
  }
  gx/=n; gy/=n;
  for(int i=0;i<n;i++){
    double px=gx+(gx-x[i]),py=gy+(gy-y[i]);
    int f=0;
    for(int j=0;j<n;j++)
      if(min(abs(px-x[j]),abs(py-y[j]))<EPS)f=1;
    if(!f)flag=0;
  }
  if(flag)printf("%.8f %.8f\n",gx,gy);
  else cout<<"NA"<<endl;
  return 0;
}