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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    
    int i,n,p=0,q=0;
    cin>>n;
    int flag=0,x[n],y[n],flag2=0;
    
    for(i=0;i<n;i++)
        {
        cin>>x[i]>>y[i];
        
        if(x==0)
            p++;
        if(y==0)
            q++;
    }
    
    for(i=1;i<n;i++)
        {
        if(x[i]!=x[0])
            {
            flag=1;
            break;
        }
    }
    
    for(i=0;i<n;i++)
        {
        if(y[i]!=y[0])
            {
            flag2=1;
            break;
        }
    }
    
    if((flag==1 && flag2==0) || (flag2==1 && flag==0))
        cout<<"YES\n";
    else
        cout<<"NO\n";
    
    return 0;
}