#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 xO, yO;
    bool xLine =  true, yLine = true;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(a0 == 0) // first iteration
         {
           xO = x;
           yO = y;
        }
        else{
            if(xO != x)
                xLine = false;
            if(yO != y)
                yLine = false;
        }
    }
    if(xLine || yLine)
        cout << "YES";
    else 
        cout << "NO";
    return 0;
}