#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 x;
        int y;
    bool h = false, v = false;
    cin >> x >> y;
    if (x == 0) {
        h = true;
    } else if (y == 0) {
        v = true;
    } else {
        cout << "NO";
        return 0;
    }
    for(int a0 = 0; a0 < n; a0++){
 
        cin >> x >> y;
        if(h == true && x != 0 ) {
            cout << "NO";
            return 0;
        }
        if(v == true && y != 0 ) {
            cout << "NO";
            return 0;
        }
    }
    cout << "YES";
    return 0;
}