#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 minx = 1e9, maxx = -1e9,
        miny = 1e9, maxy = -1e9;
    
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        
        minx = min(minx, x);
        maxx = max(maxx, x);
        miny = min(miny, y);
        maxy = max(maxy, y);
    }
    
    if(minx == maxx || miny == maxy) {
        cout << "YES";
    } else {
        cout << "NO";
    }
    return 0;
}