#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
ll dcmp(ll x){return x>0?1:x<0?-1:0;}
struct Point{ll x,y;};
typedef Point Vec;
Vec operator +(Vec a,Vec b){return {a.x+b.x,a.y+b.y};}
Vec operator -(Vec a,Vec b){return {a.x-b.x,a.y-b.y};}
ll Cro(Vec a,Vec b){return a.x*b.y-a.y*b.x;}
ll Dot(Vec a,Vec b){return a.x*b.x+a.y*b.y;}
bool PolyShape(Point *p,int n)
{
	p[0]=p[n];p[n+1]=p[1];
	for(int i=1,op=0;i<=n;i++)
	{
		int o=dcmp(Cro(p[i]-p[i-1],p[i+1]-p[i]));
		if(!o)return 0;
		if(!op)op=o;
		else if(op!=o)return 0; 
	}
	return 1;
}
const int N=1e6+3;
int n;
Point p[N];
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)cin>>p[i].x>>p[i].y;
	puts(PolyShape(p,n)?"Yes":"No");
}