#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 area(int x1,int y1,int x2,int y2,int x3, int y3){
    return (x1*(y2-y3)-y1*(x2-x3)+(x2*y3-y2*x3));
}
int main(){
    int n;
    cin >> n;
    int x[n],y[n];
    for(int a0 = 0; a0 < n; a0++){
        cin >>x[a0]>> y[a0];
    }
    for(int i=2;i<n;i++)
        if(area(x[0],y[0],x[1],y[1],x[i],y[i])!=0)
            {
        cout<<"NO";
        return 0;
    }
    cout<<"YES";
    return 0;
}