#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
#define forn(i, n) for(ll i = 0; i < (ll)n; i++)
#define fornn(i, q, n) for(ll i = (ll)q; i < (ll)n; i++)
#define parr(arr,n) for(ll i=0;i<n;i++){cout << arr[i] << " ";} cout<<endl;
#define fore(i, x) for(__typeof((x).begin()) i = (x).begin(); i != (x).end(); i ++)
#define mem(x,val) memset((x),(val),sizeof(x));
#define pb push_back
#define mp make_pair
#define p push
#define f front
#define F first
#define S second
#define pvec(vec) for(ll i=0;i<vec.size();i++){cout<<vec[i]<<" ";} cout<<endl;
#define INF 2000000000
#define MOD 1000000007
const ll maxn=2e5 + 4;
const ll MAXN=1000001;

ll power (ll x, unsigned int y)
{
    ll temp;
    if (y == 0)
        return 1;

    temp = power (x, y / 2);
    if ((y % 2) == 0)
        return temp * temp;
    else
        return x * temp * temp;
}

ll n;
vector< pair<ll,ll> > v;

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
    ll a,b;
    cin>>n;
    forn(i,n){
        cin>>a>>b;
        v.pb(mp(a,b));
    }

    int f=1;
    forn(i,v.size()-1){
        if(v[i].F!=v[i+1].F){
            f=0;
        }
    }

    if(f){
        cout<<"YES\n";
        return 0;
    }

    f=1;
    forn(i,v.size()-1){
        if(v[i].S!=v[i+1].S){
            f=0;
        }
    }

    if(f){
        cout<<"YES\n";
        return 0;
    }

    cout<<"NO\n";
    return 0;


	return 0;
}