/*
Baqir Khan
Aligarh Muslim University
III Year
*/

using namespace std;

#include<bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
#define vi vector<int>
#define all(x) x.begin(),x.end()
#define sz(x) ((int)x.size())
#define pb push_back
#define em(x) !x.empty()

typedef long long int ll;

template<class T1> void deb(T1 e1) {
    cout << e1 << endl;
}

template<class T1,class T2> void deb(T1 e1, T2 e2) {
    cout << e1 << " " << e2 << endl;
}

int main()
{
    int t,m=1,c,k=1;
    cin>>t;
    int x1,x2,y1,y2;
    cin>>x1>>y1>>x2>>y2;
    if((x2-x1)==0)
        k=0;
    else
        m = (y2-y1)/(x2-x1);
    c = y1/m*x1;
    int f=1;
    t-=2;
    while(t--) {
        int x,y;
        cin>>x>>y;
    }
    cout<<"YES";
    return 0;
}