#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 firstx;
    int firsty;
    cin >> firstx >> firsty;
    
    bool flagx = true;
    bool flagy = true;
    
    for(int a0 = 1; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        
        if (x != firstx)
        {
            flagx = false;
        }
        
        if (y != firsty)
        {
            flagy = false;
        }
    }
    
    cout << (flagx || flagy? "YES": "NO") << endl;
    
    
    return 0;
}