#include <vector>
#include <cmath>
#include <cstdlib>
#include <cstdio>
#include <algorithm>

using namespace std;
#define double long double

struct point {
    double x, y;
    point(double x=0, double y=0): x(x), y(y) {}
    point operator*(double c) const { return point(c*x, c*y); }
    point operator+(const point &p) const { return point(x+p.x, y+p.y); }
    point operator-(const point &p) const { return point(x-p.x, y-p.y); }
    point operator-() const { return point(-x, -y); }
    double dot(const point &p) const { return x*p.x + y*p.y; }
    double cross(const point &p) const { return x*p.y - y*p.x; }
    int quadrant() const {
        if (y > 0 && x >= 0) return 0;
        if (x < 0 && y >= 0) return 1;
        if (y < 0 && x <= 0) return 2;
        return 3;
    }
    bool operator<(const point &p) const {
        int q1 = quadrant(), q2 = p.quadrant();
        if (q1 != q2) return q1 < q2;
        return cross(p) > 0;
    }
};

struct ray {
    point P, dP;
    ray(point P=point(), point dP=point()): P(P), dP(dP) {}
    point isect(ray &L) const {
        double det = dP.cross(L.dP);
        double s = fabs(det) > 1e-9 ? L.dP.cross(P-L.P)/det : -1e30;
        return P + dP*s;
    }

    bool operator<(const ray &L) const {
        return dP < L.dP;
    }
};

double area(const vector<ray> &P) {
    double res = 0.0;
    for (int i = 0, j = P.size()-1; i < P.size(); j = i++)
        res += P[j].P.cross(P[i].P);
    return res/2.0;
}

int main(int argc, char **argv) {
    int n;
    scanf("%d", &n);
    vector<ray> segs(n);
    for (int i = 0; i < n; ++i)
        scanf("%Lf%Lf", &segs[i].P.x, &segs[i].P.y);
    for (int i = 0; i < n; ++i)
        segs[i].dP = (segs[(i+n-1)%n].P - segs[i].P);

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

    int d = 0;
    for (int i = 1; i < n; ++i) {
        if (segs[d] < segs[i])
            segs[++d] = segs[i];
        else if (segs[i].dP.cross(segs[i].P - segs[d].P) > 0)
            segs[d] = segs[i];
    }
    segs.resize(d+1);
    segs.push_back(segs.front());
    n = segs.size();

    vector<ray> P(1, segs[0]);

    auto add_line = [&](const ray &L) {
        auto q = L.isect(P.back());
        while (P.size() > 1 && P.back().dP.dot(q-P.back().P) <= 0) {
            P.pop_back();
            q = L.isect(P.back());
        }
        P.push_back(ray(q, L.dP));
    };

    for (int i = 1; i < n; ++i)
        add_line(segs[i]);
    int a = 0;
    while (a+1 < P.size()-1 && P[a].dP.dot(P.back().P-P[a+1].P) > 0) {
        ++a;
        P.pop_back();
        add_line(P[a]);
    }
    P = vector<ray>(P.begin() + a + 1, P.end());

    printf("%.9Lf\n", area(P));
    if (argc > 1) {
        printf("%d\n", P.size());
        for (auto &p: P)
            printf("%lf %lf\n", p.P.x, p.P.y);
    }
}