#include<cmath>
#include<cstdio>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

const double EPS=1e-8;

int main(){
	int n; scanf("%d",&n);
	int x[50],y[50];
	rep(i,n) scanf("%d%d",x+i,y+i);

	if(n%2==1){ puts("NA"); return 0; }

	double gx=0,gy=0;
	rep(i,n) gx+=x[i], gy+=y[i];
	gx/=n;
	gy/=n;

	rep(i,n){
		if(abs((x[i]+x[(i+n/2)%n])/2.0-gx)<EPS
		&& abs((y[i]+y[(i+n/2)%n])/2.0-gy)<EPS);
		else{
			puts("NA");
			return 0;
		}
	}

	printf("%.9f %.9f\n",gx,gy);

	return 0;
}