#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int n,i,j,tempx,tempy,a,b,flagx=1,flagy=1; vector <int> x,y;
    cin>>n;
    for(i=0;i<n;i++)
    {   cin>>tempx>>tempy;
        x.push_back(tempx);
        y.push_back(tempy);
    }
    a=x[0]; b=y[0];
    for(i=1;i<n;i++)
    {   if(a!=x[i])
        {    flagx=0;
             break;
        }
    }
    for(i=1;i<n;i++)
    {   if(b!=y[i])
        {    flagy=0;
             break;
        }
    }
    if(flagx==1||flagy==1)
        cout<<"YES"<<endl;
    else
        cout<<"NO"<<endl;
        /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}