#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

typedef pair <ll, ll> point;

#define x first

#define y second

int n, m;

inline ll area (point A, point B, point C) {

return A.x * B.y + B.x * C.y + C.x * A.y - A.y * B.x - B.y * C.x - C.y * A.x;

}

inline int sgn (point A, point B, point C) {

ll det = area(A, B, C);

return det ? (det > 0 ? 1 : -1) : 0;

}

inline bool intersect (point A, point B, point C, point D) {

if (sgn(A, B, C) == 0 and min(A.x, B.x) <= C.x and C.x <= max(A.x, B.x) and min(A.y, B.y) <= C.y and C.y <= max(A.y, B.y)) return 1;

if (sgn(A, B, D) == 0 and min(A.x, B.x) <= D.x and D.x <= max(A.x, B.x) and min(A.y, B.y) <= D.y and D.y <= max(A.y, B.y)) return 1;

return sgn(A, B, C) * sgn(A, B, D) == -1 and sgn(C, D, A) * sgn(C, D, B) == -1;

}

//ConvexHull

vector <point> convexHull (vector <point> p) {

int n = p.size(), m = 0;

if (n < 3) return p;

vector <point> hull(n << 1);

sort(p.begin(), p.end());

for (int i = 0; i < n; ++i) {

while (m > 1 and area(hull[m - 2], hull[m - 1], p[i]) <= 0) --m;

hull[m++] = p[i];

}

for (int i = n - 2, j = m + 1; i >= 0; --i) {

while (m >= j and area(hull[m - 2], hull[m - 1], p[i]) <= 0) --m;

hull[m++] = p[i];

}

hull.resize(m - 1); return hull;

}

int main() {

cin >> n >> m;

vector <point> outerPoly(n), innerPoly(m), cand;

for (auto &[x, y] : outerPoly) cin >> x >> y, x *= 2, y *= 2;

for (auto &[x, y] : innerPoly) cin >> x >> y, x *= 2, y *= 2;

for (auto P : outerPoly) for (auto Q : innerPoly) {

bool bad = false;

for (int i = 0; i < m; ++i) {

auto A = innerPoly[i], B = innerPoly[(i + 1) % m];

if (A == Q or B == Q) continue;

if (intersect(P, Q, A, B)) {bad = true; break;}

}

if (!bad) cand.emplace_back((P.x + Q.x) / 2, (P.y + Q.y) / 2);

}

vector <point> hull = convexHull(cand);

cout << hull.size() << '\n';

for (auto P : hull) {

printf("%lld", P.x >> 1);

if (P.x & 1) printf(".5");

printf(" ");

printf("%lld", P.y >> 1);

if (P.y & 1) printf(".5");

puts("");

}

return 0;

}