#include <iostream>

using namespace std;


int main(){
    int N,X[10],Y[10],i,s1=1,s2=1,x,y;
    cin >> N;
    for (i=0;i<N;++i)
        {
        cin >> X[i] >> Y[i];
    }
    x=X[0];
    y=Y[0];
    for (i=1;i<N;++i)
        {
        if (s1)
            if (X[i]!=x)
            s1=0;
        if (s2)
            if (Y[i]!=y)
            s2=0;
    }
    if (s1||s2)
        cout <<"YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}