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 <bits/stdc++.h>
using namespace std;
const double PI = 4 * atan(1.0);
const int MAX_SIZE = 10000;
double dot(complex<double> a, complex<double> b) {
  return (a.real() * b.real() + a.imag() * b.imag());
}
double cross(complex<double> a, complex<double> b) {
  return (a.real() * b.imag() - a.imag() * b.real());
}
int is_point_on_line(complex<double> a, complex<double> b, complex<double> c) {
  return (abs((cross(b - a, c - a)) - (0.0)) < (1e-10));
}
int is_orthogonal(complex<double> a1, complex<double> a2, complex<double> b1,
                  complex<double> b2) {
  return (abs((dot(a1 - a2, b1 - b2)) - (0.0)) < (1e-10));
}
int is_parallel(complex<double> a1, complex<double> a2, complex<double> b1,
                complex<double> b2) {
  return (abs((cross(a1 - a2, b1 - b2)) - (0.0)) < (1e-10));
}
double distance_l_p(complex<double> a, complex<double> b, complex<double> c) {
  return abs(cross(b - a, c - a)) / abs(b - a);
}
double distance_ls_p(complex<double> a, complex<double> b, complex<double> c) {
  if (dot(b - a, c - a) < (1e-10)) return abs(c - a);
  if (dot(a - b, c - b) < (1e-10)) return abs(c - b);
  return abs(cross(b - a, c - a)) / abs(b - a);
}
bool isInPolygon(vector<complex<double> > &points, complex<double> s) {
  if (points.size() == 1) return false;
  vector<complex<double> > v;
  for (int i = 0; i < (int)points.size(); i++) v.push_back(points[i] - s);
  int sign = 0;
  for (int i = 1; i <= (int)v.size(); i++) {
    int prv = (i - 1 + v.size()) % v.size();
    int cur = i % v.size();
    double c = cross(v[prv], v[cur]);
    if ((abs((c) - (0)) < (1e-10)))
      continue;
    else if (sign == 0) {
      if (c > 0)
        sign = 1;
      else
        sign = -1;
    } else {
      if (sign == -1 && c > 0)
        return false;
      else if (sign == 1 && c < 0)
        return false;
    }
  }
  return true;
}
struct Rec {
  vector<complex<double> > p;
};
int is_intersected_ls(complex<double> a1, complex<double> a2,
                      complex<double> b1, complex<double> b2) {
  if (abs(cross(a2 - a1, b2 - b1)) < (1e-10)) {
    return 0;
  }
  return (cross(a2 - a1, b1 - a1) * cross(a2 - a1, b2 - a1) < (1e-10)) &&
         (cross(b2 - b1, a1 - b1) * cross(b2 - b1, a2 - b1) < (1e-10));
}
bool isTouchRectangle(Rec &a, Rec &b) {
  for (int i = 0; i < 4; i++)
    if (isInPolygon(b.p, a.p[i])) return true;
  for (int i = 0; i < 4; i++)
    if (isInPolygon(a.p, b.p[i])) return true;
  for (int i = 0; i < 4; i++) {
    int curi = i;
    int prvi = (i - 1 + 4) % 4;
    for (int j = 0; j < 4; j++) {
      int curj = j;
      int prvj = (j - 1 + 4) % 4;
      if (is_intersected_ls(a.p[curi], a.p[prvi], b.p[curj], b.p[prvj]))
        return true;
    }
  }
  return false;
}
complex<double> intersection_ls(complex<double> a1, complex<double> a2,
                                complex<double> b1, complex<double> b2) {
  complex<double> b = b2 - b1;
  double d1 = abs(cross(b, a1 - b1));
  double d2 = abs(cross(b, a2 - b1));
  double t = d1 / (d1 + d2);
  return a1 + (a2 - a1) * t;
}
int is_intersected_l(complex<double> a1, complex<double> a2, complex<double> b1,
                     complex<double> b2) {
  return !(abs((cross(a1 - a2, b1 - b2)) - (0.0)) < (1e-10));
}
complex<double> intersection_l(complex<double> a1, complex<double> a2,
                               complex<double> b1, complex<double> b2) {
  complex<double> a = a2 - a1;
  complex<double> b = b2 - b1;
  return a1 + a * cross(b, b1 - a1) / cross(b, a);
}
complex<double> normalVector(complex<double> p) { return p / abs(p); }
complex<double> unitVector(complex<double> a) {
  return complex<double>(-a.imag(), a.real());
}
complex<double> unitNormalVector(complex<double> tmp) {
  complex<double> e = complex<double>(-tmp.imag(), tmp.real());
  e /= abs(e);
  return e;
}
complex<double> roundPoint(complex<double> p, double a) {
  return complex<double>(cos(a) * p.real() - sin(a) * p.imag(),
                         sin(a) * p.real() + cos(a) * p.imag());
}
double calcPolygonArea(vector<complex<double> > p) {
  double sum = 0;
  for (int i = 0; i < (int)p.size(); i++)
    sum += cross(p[i], p[(i + 1) % (p.size())]);
  return abs(sum / 2);
}
complex<double> ps[101];
complex<double> ps2[101];
int main() {
  int N;
  cin >> N;
  double avgx = 0, avgy = 0;
  for (int i = 0; i < N; i++) {
    double x, y;
    cin >> x >> y;
    avgx += x;
    avgy += y;
    ps[i] = complex<double>(x, y);
  }
  if (N % 2 == 1) {
    cout << "NA" << endl;
    return 0;
  }
  avgx /= N;
  avgy /= N;
  avgx = (ps[0] + ps[N / 2]).real() / 2;
  avgy = (ps[0] + ps[N / 2]).imag() / 2;
  complex<double> avgp = complex<double>(avgx, avgy);
  for (int i = 0; i < N; i++) ps[i] -= avgp;
  for (int i = 0; i < N; i++) ps2[i] = roundPoint(ps[i], PI);
  bool ok = false;
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < N; j++) {
      if (((abs(((ps[i]).real()) - ((ps2[j]).real())) < (1e-10)) &&
           (abs(((ps[i]).imag()) - ((ps2[j]).imag())) < (1e-10)))) {
        for (int k = 0; k < N; k++) {
          int a = (k + j) % N;
          int b = (k + i) % N;
          if (!((abs(((ps[a]).real()) - ((ps2[b]).real())) < (1e-10)) &&
                (abs(((ps[a]).imag()) - ((ps2[b]).imag())) < (1e-10)))) {
            cout << "NA" << endl;
            return 0;
          }
        }
        ok = true;
        break;
      }
    }
    if (ok) break;
  }
  if (ok)
    printf("%.10f %.10f\n", avgp.real(), avgp.imag());
  else
    cout << "NA" << endl;
  return 0;
}
