#include <stdio.h>
#define N 3000
int max(int a, int b) { return a > b ? a : b; }
unsigned int Z = 12345;
int rand_() {
return (Z *= 3) >> 1;
}
int xx[N], yy[N];
long long cross(int i, int j, int k) {
return (long long) (xx[j] - xx[i]) * (yy[k] - yy[i]) - (long long) (xx[k] - xx[i]) * (yy[j] - yy[i]);
}
int o;
void sort(int *ii, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
while (j < k) {
long long c = cross(o, ii[j], i_);
if (c == 0)
j++;
else if (c < 0) {
tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
i++, j++;
} else {
k--;
tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
}
}
sort(ii, l, i);
l = k;
}
}
int main() {
static int hh[N], ii[N], jj[N], dp[N][N], dq[N][N];
int n, ml, mr, h, h_, i, i0, i_, j, j_, x;
scanf("%d", &n);
i0 = -1;
for (i = 0; i < n; i++) {
scanf("%d%d", &xx[i], &yy[i]);
if (i0 == -1 || yy[i0] > yy[i])
i0 = i;
}
for (i = 0; i < n; i++)
ii[i] = i;
ii[0] = i0, ii[i0] = 0;
o = i0, sort(ii, 1, n);
for (i = 1; i < n; i++) {
i_ = ii[i];
ml = 0;
for (h = 1; h < i; h++)
if (cross(i0, ii[h], i_) < 0)
hh[ml++] = ii[h];
o = i_, sort(hh, 0, ml);
mr = 0;
for (j = i + 1; j < n; j++)
if (cross(i0, i_, ii[j]) < 0)
jj[mr++] = ii[j];
o = i_, sort(jj, 0, mr);
h = 0, j = 0, x = 0;
while (j < mr) {
h_ = h == ml ? -1 : hh[h], j_ = jj[j];
if (h < ml && cross(h_, i_, j_) < 0)
x = max(x, dq[h_][i_]), h++;
else
dp[i_][j_] = x, j++;
}
h = ml - 1, j = mr - 1, x = -1;
while (j >= 0) {
h_ = h < 0 ? -1 : hh[h], j_ = jj[j];
if (h >= 0 && cross(h_, i_, j_) > 0)
x = max(x, dp[h_][i_]), h--;
else
dq[i_][j_] = x + 1, j--;
}
}
x = 0;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
x = max(x, dq[i][j]);
if (x == 0) {
printf("0\n");
return 0;
}
printf("%d\n", (x + 1) * 2);
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
if (dq[i][j] == x)
goto out;
out:
printf("%d %d\n", xx[i0], yy[i0]);
printf("%d %d\n", xx[j], yy[j]);
printf("%d %d\n", xx[i], yy[i]);
while (1) {
for (h = 0; h < n; h++)
if (cross(i0, h, i) < 0 && cross(h, i, j) > 0 && dq[i][j] == dp[h][i] + 1) {
printf("%d %d\n", xx[h], yy[h]);
j = i, i = h;
break;
}
if (dp[i][j] == 0)
break;
for (h = 0; h < n; h++)
if (cross(i0, h, i) < 0 && cross(h, i, j) < 0 && dp[i][j] == dq[h][i]) {
printf("%d %d\n", xx[h], yy[h]);
j = i, i = h;
break;
}
}
return 0;
}
