#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#define N 3005
using namespace std;
typedef long long ll;
struct st{
ll x, y, id;
} o, a[N];
ll n, ans, d1[N][N], d2[N][N], h1[N][N], h2[N][N];
vector<st> lt, rt;
ll ccw(st p, st q, st r) {
return p.x * q.y + q.x * r.y + r.x * p.y - q.x * p.y - r.x * q.y - p.x * r.y;
}
bool cmp(st p, st q) {return ccw(o, p, q) > 0;}
bool cmpmn(st p, st q) {
if (p.y != q.y) return p.y < q.y;
else return p.x < q.x;
}
void print(ll p, ll q, ll r) {
if (p == 0) {printf("%lld %lld\n", a[p].x, a[p].y); return;}
if (r == 1) print(q, h1[p][q], 2);
else print(q, h2[p][q], 1);
printf("%lld %lld\n", a[p].x, a[p].y);
}
int main()
{
ll i, j, k;
cin >> n;
for (i = 0; i < n; i++) {
scanf("%lld %lld", &a[i].x, &a[i].y);
}
sort(a, a + n, cmpmn);
o = a[0];
sort(a + 1, a + n, cmp);
for (i = 0; i < n; i++) a[i].id = i;
for (i = 1; i < n; i++) d1[i][0] = 2;
for (i = 1; i < n; i++) {
lt.clear(); rt.clear();
rt.push_back(a[0]);
for (j = 1; j < i; j++) if (ccw(a[0], a[i], a[j])) rt.push_back(a[j]);
for (j = i + 1; j < n; j++) if (ccw(a[0], a[i], a[j])) lt.push_back(a[j]);
o = a[i];
sort(lt.begin(), lt.end(), cmp);
sort(rt.begin(), rt.end(), cmp);
ll mx = -1e9, mi = 0;
ll I = a[i].id;
for (j = 0, k = 0; j < lt.size(); j++) {
ll J = lt[j].id;
for (; k < rt.size(); k++) {
ll K = rt[k].id;
if (ccw(rt[k], a[i], lt[j]) <= 0) break;
if (d1[I][K] + 1 > mx) mx = d1[I][K] + 1, mi = K;
}
d2[J][I] = mx;
h2[J][I] = mi;
}
mx = -1e9, mi = 0;
for (j = (ll)lt.size() - 1, k = (ll)rt.size() - 1; j >= 0; j--) {
ll J = lt[j].id;
for (; k >= 0; k--) {
ll K = rt[k].id;
if (ccw(rt[k], a[i], lt[j]) >= 0) break;
if (d2[I][K] + 1 > mx) mx = d2[I][K] + 1, mi = K;
}
d1[J][I] = mx;
h1[J][I] = mi;
}
}
for (i = 0; i < n; i++) for (j = 0; j < i; j++) ans = max(ans, d1[i][j]);
if (ans <= 3) {cout << '0'; return 0;}
cout << ans << endl;
for (i = 0; i < n; i++) for (j = 0; j < i; j++) if (d1[i][j] == ans) {print(i, j, 1); return 0;}
return 0;
}
