#include <bits/stdc++.h>

using namespace std;
vector<pair<int, int>> arr;

int main(void) {
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) {
        arr.push_back(make_pair(0, 0));
        scanf("%d", &arr[i].first);
        scanf("%d", &arr[i].second);
    }
    sort(arr.begin(),arr.end());
    bool f = 1, s = 1;
    for (int j = 1; j < n; ++j) {
        if(arr[j].first!=arr[j-1].first)f = 0;
    }
    for (int j = 1; j < n; ++j) {
        if(arr[j].second!=arr[j-1].second)s = 0;
    }
    if(f || s)puts("YES");
    else puts("NO");
}