#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;
    pair<int,int> a[15];
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        a[a0].first = x;
        a[a0].second = y;
    }
    if(a[0].first==a[1].first){
        for(int i=0;i<n;i++){
            if(a[i].first!=a[0].first){
                 printf("NO\n");
                 return 0;
            }
        }
        printf("YES\n");
        return 0;
    }
    long double m = (double)(a[0].second-a[1].second)/(a[0].first-a[0].second);
    for(int i=0;i<n;i++){
        for(int j=i+1;j<n;j++){
            if(a[i].first==a[j].first){
                printf("NO\n");
                return 0;
            }
           long double m1 = (double)(a[i].second-a[j].second)/(a[i].first-a[j].first); 
            if(m1!=m){
                printf("NO\n");
                return 0;
            }
        }
    }
    printf("YES\n");
    return 0;
}