#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 xval, yval; 
    cin >> xval >> yval; 
    bool xline = true, yline = true; 
    for(int a0 = 1; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if (x!=xval) xline=false; 
        if (y!=yval) yline=false; 
        if ((xline || yline)==false) break; 
    }
    if (xline || yline) cout << "YES" << endl; 
    else cout << "NO" << endl; 
    return 0;
}