#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;

vector<pair<int,int> > a;
int main(){
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        a.push_back({x,y});
    }
    bool t = 1,r=1;
    for(int i = 1; i < a.size();i++)if(a[i].first!=a[i-1].first)t=0;
    for(int i = 1; i < a.size();i++)if(a[i].second!=a[i-1].second)r=0;
    if(r||t)cout << "YES";
        else
        cout << "NO";
    return 0;
}