#include <bits/stdc++.h>
using namespace std;
#define IC isdigit(c)
#define GC c=getchar()
void rd(auto &x) { char GC; x = 0; bool f = 0;
	for (; !IC; GC) if (c == '-') f = 1;
	for (; IC; GC) x = x * 10 + c - 48;
	if (f) x = -x;
}
void rd(auto &x, auto &...y) { rd(x); rd(y...); }
#define U(i,l,r) for(int i(l),END##i(r); i<=END##i; ++i)
#define D(i,l,r) for(int i(l),END##i(r); i>=END##i; --i)
#define ms(x, v) memset(x, v, sizeof(x))
#define meow(...) fprintf(stderr, __VA_ARGS__)
using ll = long long;

const int N = 200005;
#define x real()
#define y imag()
using P = complex<ll>;
P p[N]; int n;

int main() {
	// freopen("arrebol.in", "r", stdin);

	rd(n);
	U (i, 1, n) {
		ll a, b; rd(a, b);
		p[i] = {a, b};
	}
	sort(p + 1, p + n + 1, [&](const P &l, const P &r) {
		return l.x == r.x ? l.y < r.y : l.x < r.x;
	});
	U (i, 2, n) if (p[i] == p[i - 1]) {
		puts("No");
		exit(0);
	}

	D (i, n, 1) p[i] -= p[1];
	sort(p + 1, p + n + 1, [&](const P &l, const P &r) {
		ll cx = l.x * r.y - l.y * r.x;
		if (cx == 0) return l.x < r.x;
		return cx < 0;
	});
	p[n + 1] = p[1];
	int stk[N] {}, sp = 2; stk[1] = 1, stk[2] = 2;
	U (i, 3, n + 1) {
		P p1 = p[stk[sp]] - p[stk[sp - 1]], p2 = p[i] - p[stk[sp]];
		if (p1.x * p2.y - p1.y * p2.x >= 0) {
			puts("No");
			exit(0);
		}
		stk[++sp] = i;
	}
	puts("Yes");
}