#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;
    bool xLine = true, yLine = true;
    int currentX = -1000, currentY = -1000;
    for(int a0 = 0; a0 < n; a0++){
        int x;
        int y;
        cin >> x >> y;
        
        if (currentX == -1000) {
            currentX = x;
            currentY = y;
            continue;
        }
        
        if (x != currentX) xLine = false;
        if (y != currentY) yLine = false;
    }
    
    cout << (xLine || yLine ? "YES" : "NO") << endl;
    return 0;
}