#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main(){
    int n;
    cin >> n;
    
    int x1,x2,y1,y2;
    cin>>x1>>y1;
    cin>>x2>>y2;
    
    double DX=x2-x1;
    double DY=y2-y1;
    
    if (y2!=y1) {    // not horizontal line
        double k=DX/DY;
        
        bool yes=true;
        for(int a0 = 2; a0 < n; a0++){
            int x;
            int y;
            cin >> x >> y;

            if (y==y1) {
                yes=false;
                break;
            }
            
            double kk=(double)(x-x1)/(double)(y-y1);
            if (k!=kk) {
                yes=false;
                break;               
            }
       }
       if (yes) cout<<"YES"<<endl; else cout<<"NO"<<endl;
    }
    else {
        double k=DY/DX;
        
        bool yes=true;
        for(int a0 = 2; a0 < n; a0++){
            int x;
            int y;
            cin >> x >> y;

            if (x==x1) {
                yes=false;
                break;
            }
            
            double kk=(double)(y-y1)/(double)(x-x1);
            if (k!=kk) {
                yes=false;
                break;               
            }
       }
       if (yes) cout<<"YES"<<endl; else cout<<"NO"<<endl;
    }
   
    
    return 0;
}