#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[n],y[n];
    int fx = 0,fy = 0;
    for(int a0 = 0; a0 < n; a0++){
        cin >> x[a0] >> y[a0]; 
    }
    for(int i=1;i<n;i++){
        if(x[i]!=x[0]) fx = 1;
        if(y[i]!=y[0]) fy = 1;
    }
    if(fx == 0 || fy == 0) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}