#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(){
    bool commonLine = 1;
    bool hasCommonX = 1;
    bool hasCommonY = 1;
    int commonX;
    int commonY;
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){

        int x;
        int y;
        cin >> x >> y;
        if (a0 == 0) { commonX = x; commonY = y;}
        if (x != commonX) { hasCommonX = 0; }
        if (y != commonY) { hasCommonY = 0; }
    }
    if (!(hasCommonX || hasCommonY)) {
        commonLine = 0;
    }
    if (commonLine) {
        cout << "YES";
    } else {
        cout << "NO";
    }
    
    return 0;
}