A convex polygon consisting of N vertices is given. The coordinates of each vertex are represented counterclockwise by (X1, Y1), (X2, Y2), ……, (XN, YN). No matter what straight line passes through the point P, find the coordinates of the point P so that the areas of the two convex polygons obtained after cutting are equal.

Constraints

* All inputs are integers

* 3 ≤ N ≤ 50

* 0 ≤ | Xi |, | Yi | ≤ 1000000

* The input polygon is a simple convex polygon.

* The output must satisfy max (| X-cX |, | Y-cY |) ≤ 0.0001 when the output coordinates are (X, Y) and the exact solution is (cX, cY).

Input

The input is given in the following format.

> N
> X1 Y1
> X2 Y2
> ……
> XN YN
>

Output

If there is a point that satisfies the condition of the problem statement, the coordinates of that point

> X Y
>

Output in the format of. If the point does not exist, output "NA" on one line.

Examples

Input

4
100 100
0 100
0 0
100 0


Output

50.00000 50.00000


Input

3
100 100
0 100
0 0


Output

NA
#include<cstdio>
#include<iostream>
#include<complex>
#include<vector>
#include<algorithm>
#include<cmath>
#include<map>
#include<list>

#define EPS (1e-10)
#define EQ(a,b) (abs((a)-(b)) < EPS)
#define fs first
#define sc second
#define pb push_back
#define sz size()
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);i++)

using namespace std;

typedef complex<long double> P;
typedef pair<P,P> L;
typedef vector<P> Poly;
typedef pair<P,long double> C;

const long double PI = acos(-1);

long double rabs(long double a,long double b){
  return abs(a-b)/(a*b);
}

//for vector
P unit(P p){return p / abs(p);}

pair<P,P> norm(P p){return make_pair(p*P(0,1),p*P(0,-1));}

long double dot(P x,P y){return real(conj(x)*y);}

long double cross(P x,P y){return imag(conj(x)*y);}

//rotate a point counter-clockwise on the origin
P rotate(P v,long double s){
  return P(real(v)*cos(s) - imag(v)*sin(s), real(v)*sin(s) + imag(v)*cos(s) );
}

//return seta A
long double arg(P a,P b,P c){return acos(dot(b-a,c-a)/(abs(b-a)*abs(c-a)));}
long double arg(long double a,long double b,long double c){return acos( (b*b+c*c-a*a)/(2*b*c) );}


//for line(segment)
int ccw(P a,P b,P c){
  b -= a;c -= a;
  if (cross(b,c)>EPS) return 1;   //counter clockwise
  if (cross(b,c)<-EPS) return -1; //clockwise
  if (dot(b, c)<-EPS) return 2;   //c--a--b on line
  if (abs(b)<abs(c)) return -2;   //a--b--c on line
  return 0;                       //on segment
}

P line_cp(L a,L b){
  long double A = cross(b.sc-b.fs,b.fs-a.fs);
  long double B = cross(b.sc-b.fs,a.sc-a.fs);
  if(abs(A) < EPS){
    if(abs(B) < EPS)return a.fs; //same line
    //else assert(false);
  }
  return a.fs+(a.sc-a.fs)*A/B;
}

//for polygon

//all vertex is already sorted.
long double area(Poly p){
  if(p.size()<3)return 0;
  long double res = cross(p[p.size()-1],p[0]);
  for(int i=1;i<p.size();i++)res += cross(p[i-1],p[i]);
  return res/2;
}

//all vertex is already sorted.
Poly convex_cut(Poly p,L l){
  Poly res;
  int n = p.size();
  for(int i=0;i<n;i++){
    int nxt = (i+1)%n;
    if(ccw(l.fs,l.sc,p[i]) != -1)res.pb(p[i]);
    if(ccw(l.fs,l.sc,p[i]) * ccw(l.fs,l.sc,p[nxt]) < 0){
      res.pb( line_cp(l, L(p[i],p[nxt]) ) );
    }
  }
  return res;
}

int main(){
  int n;
  Poly p;

  scanf("%d",&n);
  p.resize(n);
  for(int i=0;i<n;i++)scanf("%Lf%Lf",&p[i].real(),&p[i].imag());
  long double s = area(p)/2;

  P a[2];
  long double lx = p[0].real(), ux = p[0].real(), ly = p[0].imag();
  for(int i=1;i<n;i++){
    lx = min(lx,p[i].real());
    ux = max(ux,p[i].real());
    ly = min(ly,p[i].imag());
  }
  a[0] = P(lx,ly-1e2); a[1] = P(ux,ly-1e2);

  L line[2];
  for(int i=0;i<2;i++){
    long double l = 0,r = PI,mid;
    P u = P(1,0);

    for(int j=0;j<100;j++){
      mid = (l+r)/2;
      L tmp = L(a[i],a[i]+rotate(u,mid));
      long double cut = area(convex_cut(p,tmp));
      if(cut + EPS < s)r = mid;
      else l = mid;
    }
    line[i] = L(a[i],a[i]+rotate(u,l));
  }
  
  P res = line_cp(line[0],line[1]);
  
  for(int i=0;i<n;i++){
    L tmp = L(res,p[i]);
    Poly hoge = convex_cut(p,tmp);
    //printf("%.20Lf\n",area(convex_cut(p,tmp)));
    if(rabs(s, area(convex_cut(p,tmp))) > EPS){
      printf("NA\n");
      return 0;
    }
  }
  printf("%.8Lf %.8Lf\n",res.real(),res.imag());
}