/*###############################################################################################################
## Author : Kim Tae Yoon (Serendipity__) ##
###############################################################################################################*/
#include <bits/stdc++.h>
#define fastio std::ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define prntyes cout<<"Yes\n";
#define prntno cout<<"No\n";
using namespace std;
// mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); // random int64 generator
typedef long long ll;
typedef unsigned long ul;
typedef unsigned long long ull;
typedef __int128 ll128;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pii;
typedef complex<double> inum;
// Macros from KACTL pdf
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef vector<int> vi;
typedef vector<double> vd;
const double PI = acos(-1);
const int INF = 0x3f3f3f3f;
const ll LLINF = 1000000000000000000LL;
const ll MAX = 200005; // depending on the problem
const ll MOD = 998244353; // depending on the problem
template <class T> int sgn(T x) { return (x > 0) - (x < 0); }
template<class T>
struct Point {
typedef Point P;
T x, y;
explicit Point(T x=0, T y=0) : x(x), y(y) {}
bool operator<(P p) const { return tie(x,y) < tie(p.x,p.y); }
bool operator==(P p) const { return tie(x,y)==tie(p.x,p.y); }
P operator+(P p) const { return P(x+p.x, y+p.y); }
P operator-(P p) const { return P(x-p.x, y-p.y); }
P operator*(T d) const { return P(x*d, y*d); }
P operator/(T d) const { return P(x/d, y/d); }
T dot(P p) const { return x*p.x + y*p.y; }
T cross(P p) const { return x*p.y - y*p.x; }
T cross(P a, P b) const { return (a-*this).cross(b-*this); }
T dist2() const { return x*x + y*y; }
double dist() const { return sqrt((double)dist2()); }
// angle to x-axis in interval [-pi, pi]
double angle() const { return atan2(y, x); }
P unit() const { return *this/dist(); } // makes dist()=1
P perp() const { return P(-y, x); } // rotates +90 degrees
P normal() const { return perp().unit(); }
// returns point rotated 'a' radians ccw around the origin
P rotate(double a) const {
return P(x*cos(a)-y*sin(a),x*sin(a)+y*cos(a)); }
friend ostream& operator<<(ostream& os, P p) {
return os << "(" << p.x << "," << p.y << ")"; }
};
typedef Point<ll> P;
int dp[2][3005][3005];
int track[2][3005][3005];
void solve() {
ll N; cin>>N;
vector<P> A(N);
for (int i=0;i<N;i++){
ll x,y; cin>>x>>y;
A[i] = P(x,y);
}
int s = 0;
for (int i=1;i<N;i++){
if (A[i].y < A[s].y){
s = i;
}
}
swap(A[0], A[s]);
ll dx,dy;
dx = A[0].x;
dy = A[0].y;
for (int i=0;i<N;i++){
A[i].x -= dx;
A[i].y -= dy;
}
sort(A.begin()+1, A.end(), [&](P l, P r){
return l.cross(r) > 0;
});
for (int j=N-1;j>=1;j--){
vector<int> L,R;
for (int i=0;i<N;i++){
if (A[j].cross(A[i]) > 0){
L.push_back(i);
}else if (A[j].cross(A[i]) < 0){
R.push_back(i);
}
}
sort(L.begin(), L.end(), [&](int l, int r){
return A[j].cross(A[l],A[r]) > 0;
});
sort(R.begin(), R.end(), [&](int l, int r){
return A[j].cross(A[l],A[r]) > 0;
});
int ls = L.size();
int rs = R.size();
int p;
// ccw = 0
p = 0;
int mx = -INF;
int pos = -1;
for (int t=0;t<rs;t++){
int i = R[t];
while(p<ls){
int k = L[p];
if (A[j].cross(A[i],A[k]) > 0){
if (mx < dp[1][k][j]+1){
mx = dp[1][k][j]+1;
pos = k;
}
++p;
}else{
break;
}
}
dp[0][j][i] = mx;
track[0][j][i] = pos;
}
// ccw = 1
p = ls-1;
mx = 2;
pos = -1;
for (int t=rs-1;t>=0;t--){
int i = R[t];
while(p>=0){
int k = L[p];
if (A[j].cross(A[i],A[k]) < 0){
if (mx < dp[0][k][j]+1){
mx = dp[0][k][j]+1;
pos = k;
}
--p;
}else{
break;
}
}
dp[1][j][i] = mx;
track[1][j][i] = pos;
}
}
int ans = 0;
int s1,s2,t=0;
for (int i=1;i<N;i++){
for (int j=i+1;j<N;j++){
if (dp[0][j][i]+1 > ans){
ans = dp[0][j][i]+1;
s1 = j;
s2 = i;
}
}
}
if (ans < 4){cout<<0; return;}
for (int i=0;i<N;i++){
A[i].x += dx;
A[i].y += dy;
}
cout<<ans<<"\n";
cout<<A[0].x<<" "<<A[0].y<<"\n";
cout<<A[s2].x<<" "<<A[s2].y<<"\n";
while(1){
if (s1==-1){break;}
cout<<A[s1].x<<" "<<A[s1].y<<"\n";
tie(s1,s2) = pi(track[t][s1][s2],s1);
t^=1;
}
}
int main() {
fastio;
int tc = 1;
// cin >> tc;
while (tc--) {
solve();
}
return 0;
}
