#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 x, y;
        int a0x, a0y;
    bool fh = true, fv = true;
    int i;
    for(i = 0; i < n; i++){
        cin >> x >> y;
        if(!i){
            a0x = x;
            a0y = y;
        }
        else if( i == 1){
            if((y == a0y) && (x == a0x)){
                fh = true;
                fv = true;
            }
            else if(y == a0y){
                fh = true;
                fv = false;
            }
            else if(x == a0x){
                fh = false;
                fv = true;
            }
            else{
                fh = fv = false;
                break;
            }
        }
        else{
            if(fh){
                if(y != a0y){
                    fh = false;
                    break;
                }
            }
            if(fv){
                if(x != a0x){
                    fv = false;
                    break;
                }
            }
        }
    }
    if(fh || fv)
        cout << "YES\n";
    else
        cout << "NO\n";
    return 0;
}