int main() { int n; int xfirst; int yfirst; bool h = true; bool v = true;

cin >> n;
vector<pair<int,int>> points(n);
cin.ignore(numeric_limits<streamsize>::max(), '\n');

for (int n_itr = 0; n_itr < n; n_itr++) 
{
    string xy_temp;
    getline(cin, xy_temp);
    vector<string> xy = split_string(xy_temp);    
    int x = stoi(xy[0]);
    int y = stoi(xy[1]);

    points[n_itr] = {x,y};
    xfirst = points[0].first;
}
    for (int i = 0; i < n;i++)
    {
        if (points[i].first != xfirst)
        {
            h = false;
            break;
        }
    }
    yfirst = points[0].second;
    for (int j = 0; j < n;j++)
    {
        if (points[j].second != yfirst)
        {
            dprintf(2,"%d <------ -------> %d\n",points[j].second,yfirst);
            v = false;
            break;
        }
    }
if (h || v)
    cout << "YES";
else
 cout << "NO";
return 0;

}