#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main()
{
    int n; 
    scanf("%d",&n);
    double x;
    double y;
    scanf("%lf %lf",&x,&y);
    double x1, y1;
    scanf("%lf %lf",&x1, &y1);
    int ans=1;
    if(x1==x)
    {
        for(int a=0; a<n-2;  a++)
        {
            scanf("%lf %lf", &x, &y);
            if(x!=x1)
            {
                ans=0;
            }
        }
    }
    else
    {
        double m = (y1-y)/(x1-x);
        double c = y1- m*x1;
        for(int a0 = 0; a0 < n-2; a0++)
        {
            scanf("%lf %lf",&x,&y);
            if(y!=(m*x + c))
            {
                ans=0;
            }
        }
    }
    if(ans)
        printf("YES\n");
    else
        printf("NO\n");
    return 0;
}