#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 allequal(vector<int> a){
    for(int i = 0 ; i < a.size()-1 ; i++){
        if(a[i]!=a[i+1])
            return 0;
    }
    return 1;
}


int main(){
    int n;
    cin >> n;
    vector<int> vx,vy;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        vx.push_back(x);
        vy.push_back(y);
    }
    if(allequal(vx)||allequal(vy))
        cout << "YES" << endl;
    else
            cout << "NO" << endl;
    return 0;
}