#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 tempx=-100;
    int tempy=-100;
    int flagx=0;
    int flagy=0;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        if(tempx==-100)tempx=x;
        else if(tempx!=x)flagx=1;
        if(tempy==-100)tempy=y;
        else if(tempy!=y)flagy=1;
    }
    if(flagx==0||flagy==0)cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}