#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>
#include<utility>

using namespace std;

using point=pair<int,int>;



bool isSame(vector<point>& inputs){
    int len=inputs.size();
    bool ver=true,hor=true;
    for(int i=1;i<len;++i){
        if(inputs[i].first!=inputs[0].first)hor=false;
        if(inputs[i].second!=inputs[0].second)ver=false;
        if(hor==false&&ver==false) return false;
    }
    
    return true;
    
    
}

int main(){
    int n;
    cin >> n;
    vector<point> inputs;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        inputs.push_back(point(x,y));
    }
    bool res=isSame(inputs);
    if(res) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}