#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, px, py;
    cin >> n;
    bool xgood=true, ygood=true;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(a0 == 0) {
            px = x; py = y;
        } else {
            if(x != px) xgood = false;
            if(y != py) ygood = false;
        }
    }
    if(xgood || ygood)
        cout<<"YES\n";
    else
        cout<<"NO\n";
    
    return 0;
}