#include <iostream>
#include <bits/stdc++.h>

using namespace std;

int main()
{
    int t,x1,x2,y1,y2,x,y;
    bool ans=true;
    scanf("%d",&t);
    scanf("%d %d %d %d",&x1,&y1,&x2,&y2);
    t-=2;
    while(t--)
    {
        scanf("%d %d",&x,&y);
        int k1=(y-y1)*(x2-x1),k2=(x-x1)*(y2-y1);
        if(k1!=k2)
            ans=false;
    }
    if(ans&&(y2-y1==0||x2-x1==0)) printf("YES");
    else    printf("NO");
    return 0;
}