#include <bits/stdc++.h>

using namespace std;

int N;

int main()
{
    scanf("%d", &N);
    vector<int> X(N), Y(N);
    for(int i=0; i<N; i++)
        scanf("%d%d", &X[i], &Y[i]);
    sort(X.begin(), X.end());
    sort(Y.begin(), Y.end());
    if(X[0]==X.back() || Y[0]==Y.back())
        printf("YES\n");
    else
        printf("NO\n");
    return 0;
}