#include<bits/stdc++.h>

using namespace std;

int a[10], b[10];

int main(){
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        a[a0] = x;
        b[a0] = y;
    }
    
    bool hor = true, ver = true;
    for (int i = 1; i < n; i++) {
        if (a[i] != a[0]) hor = false;
        if (b[i] != b[0]) ver = false;
    }
    
    cout << ((hor || ver) ? "YES" : "NO") << endl;
    
    return 0;
}