#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 x0,y0,x1,y1;
    cin>>x0>>y0>>x1>>y1;
    bool ok = true;
    for(int a0 = 0; a0 < n-2; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(((y1-y0)*(x-x1))!=((y-y1)*(x1-x0)))  ok=false;   
    }
    if(ok)  cout<<"YES"<<endl;
    else    cout<<"NO"<<endl;
    
    
    return 0;
}