#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, firstX, firstY;
    bool hor = true, vert = true;
    
    
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(a0 == 0) {
            firstX = x;
            firstY = y;
        }
        if(x != firstX) {
            vert = false;
        }
        if(y != firstY) {
            hor = false;
        }
    }
    if(hor || vert) cout << "YES" << endl;
    else cout << "NO" << endl;
    
    return 0;
}