#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;
    bool check1 = true, check2 = true;
    vector<int> x; vector<int> y;
    for(int a0 = 0; a0 < n; a0++){
        int a, b;
        cin >> a >> b;
        x.push_back(a);
        y.push_back(b);
    }
    int a = x[0], b = y[0];
    for (int i = 1; i < n; i++){
        if (x[i] != a){check1 =false;}
    }
    for (int i = 1; i < n; i++){
        if (y[i] != b){check2 =false;}
    }
    
    if (check1 || check2) {
        cout << "YES";
    }
    else cout << "NO";
    return 0;
}