#include <cstdio>
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <set>
#include <map>
#include <ctime>
#include <cstring>
#include <cassert>
#include <bitset>
#include <sstream>
#include <queue>

#define pb push_back
#define mp make_pair
#define fs first
#define sc second
#define sz(a) ((int) (a).size())
#define eprintf(...) fprintf(stderr, __VA_ARGS__)

using namespace std;

typedef long long int64;
typedef long double ldb;

const long double eps = 1e-9;
const int inf = (1 << 30) - 1;
const long long inf64 = ((long long)1 << 62) - 1;
const long double pi = acos(-1);

template <class T> T sqr (T x) {return x * x;}
template <class T> T abs (T x) {return x < 0 ? -x : x;}

int main () {
//  ios_base::sync_with_stdio(0);
//  freopen("input.txt", "rt", stdin);
//  freopen("output.txt", "wt", stdout);

    int n;
    cin >> n;

    int x0, y0;
    bool key_x = true, key_y = true;
    for (int i = 0; i < n; ++i) {
        int x, y;
        cin >> x >> y;

        if (i == 0) {
            x0 = x, y0 = y;
        }

        key_x &= (x == x0);
        key_y &= (y == y0);
    }
    
    cout << (key_x || key_y ? "YES\n" : "NO\n"); 
        
    return 0;
}