#include <iostream>
#include <algorithm>
#include <vector>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 2e3 + 10;

int n;

struct Point
{
    lf x, y;
    bool operator < (const Point u) const {return x < u.x || (x == u.x && y < u.y);}
	Point operator - (const Point u) const {return (Point){x - u.x, y - u.y};}
    lf operator * (const Point u) const {return x * u.x + y * u.y;}
}p[MAXN];

inline lf Mul(Point x, Point y) {return x.x * y.y - x.y * y.x;}
inline lf Dist(Point x) {return sqrt(x.x * x.x + x.y * x.y);}

int st[MAXN], top;
bool oc[MAXN];
vector <int> vex;

struct Data
{
    lf a, b;
    int id;
    bool operator < (const Data u) const {return a > u.a;}
};
vector <Data> g;

int main()
{
    // freopen("M.in", "r", stdin);
    // freopen("M.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(n);
    for (int i = 1, x, y; i <= n; i++) Read(x), Read(y), p[i].x = x, p[i].y = y;
    sort(p + 1, p + n + 1);
    st[1] = 1, st[2] = top = 2;
	for (int i = 3; i <= n; i++)
	{
		while (top > 1 && Mul(p[st[top]] - p[st[top - 1]], p[i] - p[st[top]]) >= 0) top--;
		st[++top] = i;
	}
	for (int i = 1; i <= top; i++) vex.push_back(st[i]), oc[st[i]] = 1;
	st[1] = 1, st[2] = top = 2;
	for (int i = 3; i <= n; i++)
	{
		while (top > 1 && Mul(p[st[top]] - p[st[top - 1]], p[i] - p[st[top]]) <= 0) top--;
		st[++top] = i;
	}
	for (int i = top - 1; i > 1; i--) vex.push_back(st[i]), oc[st[i]] = 1;
    // for (auto x : vex) cout << x << " "; cout << "\n";
    ll ans = 1;
    for (int i = 0; i < vex.size(); i++)
    {
        Point A = p[vex[i]], B = p[vex[(i == vex.size() - 1 ? 0 : i + 1)]];
        lf dstAB = Dist(A - B);
        g.clear();
        for (int j = 1; j <= n; j++)
        {
            if (oc[j]) continue;
            g.push_back(Data{(B - A) * (p[j] - A) / Dist(A - p[j]) / dstAB, (A - B) * (p[j] - B) / Dist(B - p[j]) / dstAB, j});
        }
        sort(g.begin(), g.end());
        // cout << i << ": " << A.x << " " << A.y << " " << B.x << " " << B.y << "\n";
        // for (auto it : g) cout << it.a << " " << it.b << " " << it.id << "\n";
        lf mx = -1e18;
        for (auto it : g)
            if (mx < it.b) ans++, mx = it.b;
    }
    cout << ans << "\n";
    return 0;
}

answer.code: In function ‘lf Dist(Point)’:
answer.code:89:33: error: ‘sqrt’ was not declared in this scope
   89 | inline lf Dist(Point x) {return sqrt(x.x * x.x + x.y * x.y);}
      |                                 ^~~~