#include <bits/stdc++.h>

using namespace std;

int main(){
    int n; 
    scanf("%d",&n);
    set<int> xx, yy;
    for(int a0 = 0; a0 < n; a0++){
        int x; 
        int y; 
        scanf("%d %d",&x,&y);
        xx.insert(x);
        yy.insert(y);
    }
    
    if(yy.size() == 1 || xx.size() == 1) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}