#include "bits/stdc++.h"
 
#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
 
using namespace std;
 
/* ??????????????¬ */
#include <complex>
 
typedef long double ld;
typedef complex<ld> Point;//????´???°
 
const ld eps = 1e-9, pi = acos(-1.0);
 
namespace std {
    bool operator<(const Point &lhs, const Point &rhs) {
        if (lhs.real() < rhs.real() - eps) return true;
        if (lhs.real() > rhs.real() + eps) return false;
        return lhs.imag() < rhs.imag();
    }
}
 
// ????????\???
Point input_point() {
    ld x, y;
    cin >> x >> y;
    return Point(x, y);
}
 
// ????????????????????????
bool eq(ld a, ld b) {
    return (abs(a - b) < eps);
}
 
// ??????
ld dot(Point a, Point b) {
    return real(conj(a) * b);//conj::??±???????´???°
}
 
// ??????
ld cross(Point a, Point b) {
    return imag(conj(a) * b);
}
 
// ??´????????????
class Line {
public:
    Point a, b;
    Line() : a(Point(0, 0)), b(Point(0, 0)) {}
    Line(Point a, Point b) : a(a), b(b) {}
};
 
/*int main(){
Point a(1,1),b(2,2);
Line l(a,b);
}*/
 
// ????????????
class Circle {
public:
    Point p;
    ld r;
    Circle() : p(Point(0, 0)), r(0) {}
    Circle(Point p, ld r) : p(p), r(r) {}
};
 
// CCW::counter clockwise
int ccw(Point a, Point b, Point c) {
    b -= a; c -= a;
    if (cross(b, c) > eps) return 1;   // a,b,c??????????¨???¨?????????????????¶
    if (cross(b, c) < -eps) return -1; // a,b,c???????¨???¨?????????????????¶
    if (dot(b, c) < 0) return 2;       // c,a,b???????????´???????????¶
    if (norm(b) < norm(c)) return -2;  // a,b,c???????????´???????????¶
    return 0;                          // a,c,b???????????´???????????¶
}
 
 
/* ???????????? */
 
// ??´?????¨??´??????????????????
//l::??´??????s::??????
bool isis_ll(Line l, Line m) {
    return !eq(cross(l.b - l.a, m.b - m.a), 0);
}
 
// ??´?????¨????????????????????? *slide??????
bool isis_ls(Line l, Line s) {
    return isis_ll(l, s) &&
        (cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < eps);
}
 
// ????????¨?????????????????????
bool isis_ss(Line s, Line t) {
    return ccw(s.a, s.b, t.a) * ccw(s.a, s.b, t.b) <= 0 &&
        ccw(t.a, t.b, s.a) * ccw(t.a, t.b, s.b) <= 0;
}
 
// ????????´????????????
bool isis_lp(Line l, Point p) {
    return (abs(cross(l.b - p, l.a - p)) < eps);
}
 
// ?????????????????????
bool isis_sp(Line s, Point p) {
    return (abs(s.a - p) + abs(s.b - p) - abs(s.b - s.a) < eps);
}
 
// ??????????¶?
Point proj(Line l, Point p) {
    ld t = dot(p - l.a, l.a - l.b) / norm(l.a - l.b);
    //norm::??¶?????????2???
    return l.a + t * (l.a - l.b);
}
 
// ??´?????¨??´????????????
Point is_ll(Line s, Line t) {
    Point sv = s.b - s.a, tv = t.b - t.a;
    assert(cross(sv, tv) != 0);
    return s.a + sv * cross(tv, t.a - s.a) / cross(tv, sv);
}
 
// ??´?????¨???????????¢
ld dist_lp(Line l, Point p) {
    return abs(p - proj(l, p));
}
 
// ??´?????¨??´???????????¢
ld dist_ll(Line l, Line m) {
    return isis_ll(l, m) ? 0 : dist_lp(l, m.a);
}
 
// ??´?????¨??????????????¢
ld dist_ls(Line l, Line s) {
    return isis_ls(l, s) ? 0 : min(dist_lp(l, s.a), dist_lp(l, s.b));
}
 
// ????????¨???????????¢
ld dist_sp(Line s, Point p) {
    Point r = proj(s, p);
    return isis_sp(s, r) ? abs(r - p) : min(abs(s.a - p), abs(s.b - p));
}
 
// ????????¨??????????????¢
ld dist_ss(Line s, Line t) {
    if (isis_ss(s, t)) return 0;
    return min({ dist_sp(s, t.a), dist_sp(s, t.b), dist_sp(t, s.a), dist_sp(t, s.b) });
}
 
 
/* ??? */
 
// ?????¨????????????
vector<Point> is_cc(Circle c1, Circle c2) {
    vector<Point> res;
    ld d = abs(c1.p - c2.p);
    ld rc = (d * d + c1.r * c1.r - c2.r * c2.r) / (2 * d);
    ld dfr = c1.r * c1.r - rc * rc;
    if (abs(dfr) < eps) dfr = 0.0;
    else if (dfr < 0.0) return res; // no intersection
    ld rs = sqrt(dfr);
    Point diff = (c2.p - c1.p) / d;
    res.push_back(c1.p + diff * Point(rc, rs));
    if (dfr != 0.0) res.push_back(c1.p + diff * Point(rc, -rs));
    return res;
}
 
// ?????¨??´????????????
vector<Point> is_lc(Circle c, Line l) {
    vector<Point> res;
    ld d = dist_lp(l, c.p);
    if (d < c.r + eps) {
        ld len = (d > c.r) ? 0.0 : sqrt(c.r * c.r - d * d); //safety;
        Point nor = (l.a - l.b) / abs(l.a - l.b);
        res.push_back(proj(l, c.p) + len * nor);
        res.push_back(proj(l, c.p) - len * nor);
    }
    return res;
}
 
// ?????¨??????????????¢
vector<Point> is_sc(Circle c, Line l) {
    vector<Point> v = is_lc(c, l), res;
    for (Point p : v)
        if (isis_sp(l, p)) res.push_back(p);
    return res;
}
 
// ?????¨????????\???
vector<Line> tangent_cp(Circle c, Point p) {
    vector<Line> ret;
    Point v = c.p - p;
    ld d = abs(v);
    ld l = sqrt(norm(v) - c.r * c.r);
    if (isnan(l)) { return ret; }
    Point v1 = v * Point(l / d, c.r / d);
    Point v2 = v * Point(l / d, -c.r / d);
    ret.push_back(Line(p, p + v1));
    if (l < eps) return ret;
    ret.push_back(Line(p, p + v2));
    return ret;
}
 
// ?????¨????????\???
vector<Line> tangent_cc(Circle c1, Circle c2) {
    vector<Line> ret;
    if (abs(c1.p - c2.p) - (c1.r + c2.r) > -eps) {
        Point center = (c1.p * c2.r + c2.p * c1.r) / (c1.r + c2.r);
        ret = tangent_cp(c1, center);
    }
    if (abs(c1.r - c2.r) > eps) {
        Point out = (-c1.p * c2.r + c2.p * c1.r) / (c1.r - c2.r);
        vector<Line> nret = tangent_cp(c1, out);
        ret.insert(ret.end(), ALL(nret));
    }
    else {
        Point v = c2.p - c1.p;
        v /= abs(v);
        Point q1 = c1.p + v * Point(0, 1) * c1.r;
        Point q2 = c1.p + v * Point(0, -1) * c1.r;
        ret.push_back(Line(q1, q1 + v));
        ret.push_back(Line(q2, q2 + v));
    }
    return ret;
}
 
 
/* ????§???¢ */
 
typedef vector<Point> Polygon;
 
// ??¢???
ld area(const Polygon &p) {
    ld res = 0;
    int n = p.size();
    REP(j, n) res += cross(p[j], p[(j + 1) % n]);
    return res / 2;
}
 
// ????§???¢????????¢??????
bool is_counter_clockwise(const Polygon &poly) {
    ld angle = 0;
    int n = poly.size();
    REP(i, n) {
        Point a = poly[i], b = poly[(i + 1) % n], c = poly[(i + 2) % n];
        angle += arg((c - b) / (b - a));
    }
    return angle > eps;
}
 
// ??????????????????
// -1 => out
//  0 => on
//  1 => in
int is_in_polygon(const Polygon &poly, Point p) {
    ld angle = 0;
    int n = poly.size();
    REP(i, n) {
        Point a = poly[i], b = poly[(i + 1) % n];
        if (isis_sp(Line(a, b), p)) return 1;
        angle += arg((b - p) / (a - p));
    }
    return eq(angle, 0) ? 0 : 2;
}
 
// ??????
Polygon convex_hull(vector<Point> ps) {
    int n = ps.size();
    int k = 0;
    sort(ps.begin(), ps.end());
    Polygon ch(2 * n);
    for (int i = 0; i < n; ch[k++] = ps[i++])
        while (k >= 2 && ccw(ch[k - 2], ch[k - 1], ps[i]) <= 0) --k;
    for (int i = n - 2, t = k + 1; i >= 0; ch[k++] = ps[i--])
        while (k >= t && ccw(ch[k - 2], ch[k - 1], ps[i]) <= 0) --k;
    ch.resize(k - 1);
    return ch;
}
 
// ????????????
Polygon convex_cut(const Polygon &ps, Line l) {
    int n = ps.size();
    Polygon Q;
    REP(i, n) {
        Point A = ps[i], B = ps[(i + 1) % n];
        Line m = Line(A, B);
        if (ccw(l.a, l.b, A) != -1) Q.push_back(A);
        if (ccw(l.a, l.b, A) * ccw(l.a, l.b, B) < 0 && isis_ll(l, m))
            Q.push_back(is_ll(l, m));
    }
    return Q;
}
 
typedef pair<ld, ld> P;
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
 
    int n;cin>>n;
    vector<P> v(n);
    for(int i=0;i<n;i++){
        ld x,y;cin>>x>>y;
        v[i]=P(x,y);
    }
    ld ma=0;
    P mid;
    for(int i=0;i<n;i++){
        for(int j=i+1;j<n;j++){
            ld len= (v[i].first-v[j].first)*(v[i].first-v[j].first)+(v[i].second-v[j].second)*(v[i].second-v[j].second);
            if(len>ma){
                ma=len;
                mid= P((v[i].first+v[j].first)/2,(v[i].second+v[j].second)/2);
            }
        }
    }
//    cout<<mid.first<<" "<<mid.second<<endl;
//    cout<<ma<<endl;
    if(ma==0) cout<<"NA"<<endl;
    else{
        for(int i=0;i<n;i++){
            bool flag=false;
            for(int j=0;j<n;j++){
                P mi=P((v[i].first+v[j].first)/2,(v[i].second+v[j].second)/2);
                if(eq(mi.first,mid.first)&&eq(mi.second,mid.second)){
                    flag=true;break;
                }
            }
            if(!flag){
                cout<<"NA"<<endl;
                return 0;
            }
        }
         
        cout<<fixed<<setprecision(10)<<mid.first<<" "<<mid.second<<endl;
    }
}


Measured memory_bytes: 3312