import java.util.*;
class Line 
{	public static void main(String args[])
	{	Scanner in= new Scanner (System.in);
		int n,a,b,c;
		c=0;
		
		n=in.nextInt();
		int x[]= new int[n];
		int y[]= new int[n];
		for(int i=0; i<n;i++)
		{	a=in.nextInt();
			b=in.nextInt();
			x[i]=a;
			y[i]=b;
		}
		for( int i=0;i<n-2;i++)
		{	if(!((y[i]-y[i+1])*(x[i]-x[i+2]) == (y[i]-y[i+2])*(x[i]-x[i+1])))
			{	c=1;
				break;
			}
		}
		if(c==0)
			System.out.println("YES");
		else
			System.out.println("NO");
	}
}