#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;

typedef unsigned int uint;
typedef unsigned long long uint64;
typedef long long sint64;

int main(int argc, char* argv[])
{
    uint n;
    cin >> n;

    bool sx = true,
         sy = true;

    int px, py;
    cin >> px >> py;
    --n;

    for (; n; --n) {
        int x, y;
        cin >> x >> y;
        if (x != px)
            sx = false;
        if (y != py)
            sy = false;
    }

    if (sx || sy)
        cout << "YES\n";
    else
        cout << "NO\n";
    return 0;
}