#include <iostream>
#include <iosfwd>
#include <iomanip>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <cassert>
#include <cctype>
#include <climits>
#include <vector>
#include <bitset>
#include <set>
#include <queue>
#include <stack>
#include <map>
#include <deque>
#include <string>
#include <list>
#include <iterator>
#include <sstream>
#include <complex>
#include <fstream>
#include <functional>
#include <numeric>
#include <utility>
#include <algorithm>
#include <assert.h>
#include <unordered_map>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef double ld;
typedef vector < long long > vll;
typedef pair <long long, long long> pll;
typedef pair <int, int> pii;
typedef vector < int > vii;
typedef complex < double > Point;

#define csl ios_base::sync_with_stdio(false); cin.tie(NULL)
#define mp make_pair
#define fst first
#define snd second
#define prev PREV
ll t, n, m, u, v, q, r, ql, qr, k, l, s, w, c, z, d, b;
const int N = 2e5 + 500;
const long long mod = 1e9 + 7;
const long long INF = 1LL << 52LL;
pll pt[N];;
int main() {
    csl;
    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> pt[i].fst >> pt[i].snd;
    bool x = true, y = true;
    for (int i = 2; i <= n; ++i) {
        if (pt[i].fst != pt[i - 1].fst)
            x = false;
        if (pt[i].snd != pt[i - 1].snd)
            y = false;
    }
    if (x || y)
        cout << "YES\n";
    else cout << "NO\n";
    return 0;
}