#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 3000;
const ll INF = 1e9;
struct Point { ll x, y; };
bool operator == (const Point &p, const Point &q) { return p.x==q.x && p.y==q.y; }
Point operator + (const Point &p, const Point &q) { return {p.x+q.x, p.y+q.y}; }
Point operator - (const Point &p, const Point &q) { return {p.x-q.x, p.y-q.y}; }
ll ccw(Point p, Point q) { return p.x*q.y-p.y*q.x; }
ll ccw(Point p, Point q1, Point q2) { return ccw(q1-p, q2-p); }
int N;
Point A[MAXN+10], P={INF, INF};
pii dp1[MAXN+10][MAXN+10], dp2[MAXN+10][MAXN+10];
pair<int, pii> ans;
int main()
{
int i, j, k;
ans.first=-987654321;
scanf("%d", &N);
for(i=1; i<=N; i++) scanf("%lld%lld", &A[i].x, &A[i].y);
for(i=1; i<=N; i++) if(A[i].y<P.y) P=A[i];
for(i=1; i<=N; i++) if(A[i]==P) break;
for(; i<N; i++) swap(A[i], A[i+1]);
N--;
sort(A+1, A+N+1, [&](const Point &p, const Point &q) { return ccw(P, p, q)<0; });
for(i=1; i<=N; i++)
{
vector<int> L, R;
for(j=i+1; j<=N; j++) R.push_back(j), dp1[j][i+1]=dp2[j][i+1]={-987654321, 0};
for(j=1; j<i; j++) L.push_back(j);
sort(L.begin(), L.end(), [&](const int &p, const int &q) { return ccw(A[i]-A[p], A[i]-A[q])<0; });
sort(R.begin(), R.end(), [&](const int &p, const int &q) { return ccw(A[p]-A[i], A[q]-A[i])<0; });
pii now={2, i};
for(j=0, k=0; j<R.size(); j++)
{
for(; k<L.size() && ccw(A[i]-A[L[k]], A[R[j]]-A[i])<0; k++) now=max(now, {dp2[L[k]][i].first+1, L[k]});
dp1[i][R[j]]=max(dp1[i][R[j]], now);
}
now={-987654321, 0};
for(j=R.size()-1, k=L.size()-1; j>=0; j--)
{
for(; k>=0 && ccw(A[i]-A[L[k]], A[R[j]]-A[i])>0; k--) now=max(now, {dp1[L[k]][i].first+1, L[k]});
dp2[i][R[j]]=max(dp2[i][R[j]], now);
ans=max(ans, {dp2[i][R[j]].first, {i, R[j]}});
}
}
if(ans.first==-987654321) return !printf("0\n");
vector<Point> V;
pii v=ans.second; int t=2;
V.push_back(P);
while(1)
{
V.push_back(A[v.second]);
if(v.first==v.second) break;
if(t==2)
{
v={dp2[v.first][v.second].second, v.first};
t=1;
}
else
{
v={dp1[v.first][v.second].second, v.first};
t=2;
}
}
assert(V.size()==ans.first+1);
printf("%d\n", V.size());
for(auto it : V) printf("%lld %lld\n", it.x, it.y);
}
