#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 arrx[n], arry[n];
    int flagx = 0, flagy = 0;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        arrx[a0] = x;
        arry[a0] = y;
    }
    for(int a0 = 0; a0 < n-1; a0++){
        if(arrx[a0] != arrx[a0+1]){
            flagx = 1;
            break;
        }
    }
    
    for(int a0 = 0; a0 < n-1; a0++){
        if(arry[a0] != arry[a0+1]){
            flagy = 1;
            break;
        }
    }

    if(flagx == 0 || flagy == 0){
        cout<<"YES";
    }
    else{
        cout<<"NO";
    }
    return 0;
}