#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 x[20], y[20];

int main(){
    int n;
    cin >> n;
    for(int a0 = 0; a0 < n; a0++){
        cin >> x[a0] >> y[a0];
    }
    bool ans = false;
    bool cur = true;
    for (int i = 0; i < n; ++i)
        if (x[i] != x[0])
            cur = false;
    if (cur == true)
        ans = true;
    cur = true;
    for (int i = 0; i < n; ++i)
        if (y[i] != y[0])
            cur = false;
    if (cur)
        ans = true;
    if (ans)
        cout << "YES";
    else
        cout << "NO";
    return 0;
}