#include <stdio.h>
#include <limits.h>
#include<stdlib.h>

int main()
{
    int n,i,x1,x2,y1,y2,co=0;
    scanf("%d",&n);
    scanf("%d %d",&x1,&y1);
    scanf("%d %d",&x2,&y2);
    int a=y2-y1,b=x1-x2,c=y1*(x2-x1)-x1*(y2-y1);
    //printf("\nline is %dx+%dy+%d\n",a,b,c);
    for(i=2;i<n;i++)
    {
        scanf("%d %d",&x1,&y1);

        if(a*x1 + b*y1 + c !=0 && co==0)
        {
            printf("NO");
            co=1;
        }

    }
    if(co==0)
        printf("YES");

}