#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 x, y, xPrev, yPrev;
    bool horizontal = true;
    bool vertical = true;
    for(int i=0;i<n;i++){
        cin>>x>>y;
        if(i>0){
            if(x!=xPrev) vertical = false;
            if(y!=yPrev) horizontal = false;
        }
        xPrev = x;
        yPrev = y;
    }
    if(horizontal && vertical)
        cout<<"NO";
    if(horizontal || vertical)
        cout<<"YES";
    else
        cout<<"NO";
    return 0;
}