#include <bits/stdc++.h>
#define entire(X) X.begin(),X.end()
#define LAMB [](point const &a, point const &b)->bool
using namespace std; typedef long long ll;
void OJize(){cin.tie(NULL); ios_base::sync_with_stdio(false);}
struct point{
ll x, y;
point(ll x, ll y): x{x}, y{y} {}
};
ostream &operator<<(ostream &os, point const &p){
return os << p.x << ' ' << p.y;
}
// positive -> ccw; negative -> cw; 0 -> collinear
ll ccw(point a, point b, point c){
return (b.x-a.x)*(c.y-a.y) - (b.y-a.y)*(c.x-a.x);
}
int dp[2][3003][3003];
int prv[2][3003][3003];
vector<point> pnts;
int main(){OJize();
int n; cin>>n;
for(int i=0; i<n; i++){
ll x, y; cin>>x>>y;
pnts.push_back(point(x, y));
}
sort(entire(pnts), LAMB{return a.y < b.y;});
sort(pnts.begin()+1, pnts.end(), LAMB{return ccw(pnts[0], a, b) > 0;});
// subtask 1
if(n > 300){
cout << n << '\n';
for(auto &p: pnts) cout<<p<<'\n';
return 0;
}
// base case
for(int i=1; i<n; i++) dp[0][0][i] = 2; // 0 = heel
// update
for(int i=0; i<n; i++) for(int j=i+1; j<n; j++){
// last edge is i->j
for(int k=j+1; k<n; k++){
if(ccw(pnts[j], pnts[k], pnts[0]) == 0) continue;
ll dr = ccw(pnts[i], pnts[j], pnts[k]);
if(dr < 0 && dp[0][j][k] <= dp[1][i][j] && dp[1][i][j])
dp[0][j][k] = dp[1][i][j]+1, prv[0][j][k] = i;
if(dr > 0 && dp[1][j][k] <= dp[0][i][j] && dp[0][i][j])
dp[1][j][k] = dp[0][i][j]+1, prv[1][j][k] = i;
}
}
// answer
int ans = 0, ai = 0, aj = 0;
for(int i=1; i<n; i++) for(int j=i+1; j<n; j++){
if(ccw(pnts[i], pnts[j], pnts[0]) <= 0) continue;
if(ans < dp[0][i][j]) ans = dp[0][i][j], ai = i, aj = j;
}
if(ans == 0){cout << 0; return 0;}
vector<int> trace = {aj, ai};
while(trace.back()){
int sz = trace.size();
trace.push_back(prv[sz%2][trace[sz-1]][trace[sz-2]]);
}
reverse(entire(trace));
cout<<trace.size()<<'\n';
for(int x: trace) cout<<pnts[x]<<'\n';
}
