/*

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*/
#include<bits/stdc++.h>
using namespace std;
typedef   long long ll;
typedef double LD;
constexpr ll P = 1e9;
const int N = 1e5 + 50;
const int M = 500010;
const double PI = acos(-1);
const LD eps = 1e-8;
#define INF  10000000007
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll  Exgcd(ll a, ll b, ll& x, ll& y) {
	if (!b)
	{
		x = 1, y = 0;
		return a;
	}
	ll d = Exgcd(b, a % b, y, x);
	y -= a / b * x;
	return d;
}
ll n, m, k, x, y, z, l, r, u, v, w;
ll   cnt1, res, anss1, anss, sum[M];
string  s, ss, sss;
ll  p, t, rr;
char xx;
vector<ll>vv[M];
ll b[M], d[M][3], ans, summ[M];
ll a[M][3];
struct point {
	LD x, y;
	point operator + (const point& a) const { return { x + a.x, y + a.y }; }
	point operator - (const point& a) const { return { x - a.x, y + a.y }; }
	point operator * (const LD a) const { return { x * a, y * a }; }
};
struct line {
	point s, t;
};
int sgn(LD x) {
	return x > eps ? 1 : (x < -eps ? -1: 0);
}
LD dot(const point& a, const point& b) {
	return a.x * a.x + a.y * a.y;
}
LD det(const point& a, const point& b) {
	return a.x * b.y - b.x * a.y;
}
bool turn_left(const point& a,
	const point& b,
	const point& c) {
	return sgn(det(b - a, c - a)) > 0;
}
bool cmp(point x, point y)
{
	return (x.x < y.x) || (x.x == y.x && x.y < y.y);
}
vector <point> convex_hull(vector <point> a) {
	if (a.size() <= 2) return a; //或 者 return {};
	sort(a.begin(), a.end(),cmp); //字 典 序: less <pair >
	vector <point > ret;
	for (int i = 0; i < (int)a.size(); i++) {
		while (ret.size() > 1
			&& !turn_left(ret[ret.size() - 2], ret[ret.size() - 1], a[i]))
			ret.pop_back();
		ret.push_back(a[i]);

	}
	int fixed = (int)ret.size();
	for (int i = (int)a.size() - 2; i >= 0; --i) {
		while (ret.size() > fixed
			&& !turn_left(ret[ret.size() - 2], ret[ret.size() - 1], a[i]))
			ret.pop_back();
		ret.push_back(a[i]);
	}
	ret.pop_back(); return ret; //或 者 在 ret.size() <= 2 时 return {};

}
void solve()
{
	cin >> n;
	vector<point>a;
	for (int i = 1; i <= n; i++)
	{
		cin >> x >> y;
		point z = { x,y };
		a.push_back(z);
	}
	vector<point> vv;
	vv = convex_hull(a);
	map<pair<LD, LD>, ll>mp;
	ll ans = 0;
	for (auto x : vv)
	{
		mp[{x.x, x.y}]++;
		if (mp[{x.x, x.y}] == 1)
		{
			ans++;
		}
	}
	if ( ans== n)
	{
		cout << "Yes\n";
	}
	else
	{
		cout << "No\n";
	}
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	int T = 1;
	//cin >> T;
	while (T--)
	{
		solve();
	}
	return 0;
}


//ll pri[M], st[M], phi[M];
//void is_prime(ll n)
//{
//	phi[1] = 1;
//	for (register int i = 2; i <= n; i++)
//	{
//		if (!st[i])pri[++cnt] = i, phi[i] = i - 1;
//		for (int j = 1; j <= cnt && pri[j] <= n / i; j++)
//		{
//			st[pri[j] * i] = 1;
//			if (i % pri[j] == 0)
//			{
//				phi[i * pri[j]] = phi[i] * pri[j];
//				break;
//			}
//			else
//			{
//				phi[i * pri[j]] = phi[i] * phi[pri[j]];
//			}
//		}
//	}
//}


//int bsgs(int a, int b, int p)
//{
//	int k = sqrt(p) + 1;
//	unordered_map<int, int>mp
//	for (int i = 0, j = b % p; i < k; i++)
//	{
//		mp[j] = i;
//		j = 1LL * j * a % p;
//	}
//	int ak = fpm(a, k, p);
//	for (int i = 1, j = ak % p; i <= k; i++)
//	{
//		if (mp.count(j))return 1LL * i * k - mp[j];
//		j = 1LL * j * ak % p;
//	}
//	return-2;
//}
//int exbsgs(int a, int b, int p)
//{
//	b = (b % p + p) % p;
//	if (1 % p == b % p)return 0;
//	int d = Exgcd(a, p, x, y);
//	if (d > 1)
//	{
//		if (b % d) return -INF;
//		Exgcd(a / d, p / d, x, y);
//		return exbsgs(a, b / d * x % (p / d), p / d) + 1;
//	}
//	else
//	{
//		return bsgs(a, b, p);
//	}
//}