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;
constexpr double EPS = 1e-8;
struct point {
  double x, y;
  point(double x = 0.0, double y = 0.0) : x(x), y(y) {}
  point(const point &p) : x(p.x), y(p.y) {}
  point operator+(const point &p) const { return point(x + p.x, y + p.y); }
  point operator-(const point &p) const { return point(x - p.x, y - p.y); }
  point operator*(double s) const { return point(x * s, y * s); }
};
double dot(const point &a, const point &b) { return a.x * b.x + a.y * b.y; }
double cross(const point &a, const point &b) { return a.x * b.y - a.y * b.x; }
double norm(const point &p) { return p.x * p.x + p.y * p.y; }
int ccw(const point &a, point b, point c) {
  b = b - a;
  c = c - a;
  const double t = cross(b, c);
  if (t > EPS) return 1;
  if (t < -EPS) return -1;
  if (dot(b, c) < 0) return 2;
  if (norm(b) < norm(c)) return -2;
  return 0;
}
point rotate(const point &p, double theta) {
  const double s = sin(theta), c = cos(theta);
  return point(c * p.x - s * p.y, s * p.x + c * p.y);
}
struct line {
  point a, b;
  line(const point &a_, const point &b_) : a(a_), b(b_) {}
};
point crosspoint(const line &a, const line &b) {
  const double t = cross(a.b - a.a, b.b - b.a);
  if (abs(t) < EPS) return a.a;
  return b.a + (b.b - b.a) * cross(a.b - a.a, a.a - b.a) * (1 / t);
}
double area(const vector<point> &p) {
  const int n = p.size();
  if (n < 3) return 0.0;
  double res = cross(p[n - 1], p[0]);
  for (int i = 1; i < n; ++i) {
    res += cross(p[i - 1], p[i]);
  }
  return abs(res) * 0.5;
}
vector<point> convex_cut(const vector<point> &p, const line &l) {
  const int n = p.size();
  vector<point> res;
  for (int i = 0; i < n; ++i) {
    const int next = (i + 1) % n;
    const int tmp = ccw(l.a, l.b, p[i]);
    if (tmp != -1) res.emplace_back(p[i]);
    if (tmp * ccw(l.a, l.b, p[next]) < 0) {
      res.emplace_back(crosspoint(l, line(p[i], p[next])));
    }
  }
  return res;
}
bool ok(const point &g, const vector<point> &p) {
  const double S_half = area(p) / 2.0;
  for (double theta = 0; theta < M_PI; theta += 1.0) {
    const double S =
        area(convex_cut(p, line(g, g + rotate(point(1, 0), theta))));
    if (abs(S_half - S) > EPS) return false;
  }
  return true;
}
int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout.precision(5);
  cout.flags(ios::fixed);
  int n;
  cin >> n;
  point g(0, 0);
  vector<point> p;
  p.reserve(n);
  for (int i = 0; i < n; ++i) {
    int x, y;
    cin >> x >> y;
    p.emplace_back(x, y);
    g = g + p[i];
  }
  g = g * (1.0 / n);
  if (ok(g, p)) {
    cout << g.x << " " << g.y << endl;
  } else {
    cout << "NA" << endl;
  }
  return EXIT_SUCCESS;
}
