#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;
    int x[10], y[10];
    for(int a0 = 0; a0 < n; a0++){
         cin >> x[a0] >> y[a0];
    }
    int xcount = 0, ycount = 0;
    for(int i = 1; i < n ; i++) {
        if(x[0] == x[i])
            xcount++;
        if(y[0] == y[i])
            ycount++;
    }
    if(xcount == n-1 || ycount == n-1)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}