#include <bits/stdc++.h>
#define lli long long int
#define pb push_back
#define mod 1000000007

using namespace std;

int main()
{
    int n,i,j,x,y,a,b;
    cin>>n;
    cin>>a>>b;
    bool ok1=true,ok2=true;
    for(i=1;i<n;i++){
        cin>>x>>y;
        if(x!=a)ok1=false;
        if(y!=b)ok2=false;

    }
    if(ok1 || ok2)cout<<"YES";
    else cout<<"NO";
    return 0;
}