#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int i,n;
    bool flag=true;
    cin>>n;
    double x1,x2,y1,y2,x,y;
    cin>>x1>>y1>>x2>>y2;
    if(x1==x2){
        for(i=3;i<=n;i++){
            cin>>x>>y;
            if(x!=x1){
                flag=false;
                break;
            }
        }
    }
    else if(y1==y2){
        for(i=3;i<=n;i++){
            cin>>x>>y;
            if(y!=y1){
                flag=false;
                break;
            }
        }
    }
    else{
        double m=(y2-y1)/(x2-x1);
        for(i=3;i<=n;i++){
            cin>>x>>y;
            if((y-y1)!=m*(x-x1)){
                flag=false;
                break;
            }
        }
    }
    if(flag){
        cout<<"YES";
    }
    else{
        cout<<"NO";
    }
    return 0;
}