#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main(){
    int n;
    cin >> n;
    int ox, oy,x,y;
    cin>>ox>>oy;
    cin>>x>>y;
    bool v = false,h = false;
    if(abs(ox) == abs(x))
        v = true;
    else if(abs(oy) == abs(y))
        h = true;
    if(!v && !h)
        cout<<"NO";
    else
    {
      if(v)
      {
         for(int a0 = 2; a0 < n; a0++){
             ox = abs(x); oy = abs(y);  
            cin >> x >> y;
            if(ox != abs(x))
                {
                v = false;
                break;
            }
          }
          if(!v)
              cout<<"NO";
          else
              cout<<"YES";
      }
        else
            {
              for(int a0 = 2; a0 < n; a0++){
                ox = abs(x); oy = abs(y);  
                cin >> x >> y;
                if(oy != abs(y))
                 {
                   h = false;
                   break;
                }  
          }
          if(!h)
            cout<<"NO";
          else
            cout<<"YES";
            
        }
    }
    return 0;
}