#include <iostream>

using namespace std;

int main(){
    int n;
    cin >> n;
    int x = 0, y = 0;
    int oldX = 0, oldY = 0;
    bool sameX = true, sameY = true;
    cin >> x >> y;
    oldX = x;
    oldY = y;
    int count = 0;
    while((sameX || sameY) && count != n-1) {
        cin >> x >> y;
        if(oldX != x)
            sameX = false;
        if(oldY != y)
            sameY = false;
        count++;
    }
    if(sameX || sameY)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    
    return 0;
}