#include<bits/stdc++.h>
using namespace std;
#define test int t;scanf("%d", &t);while(t--)
#define sd(n) scanf("%d", &n)
#define loop(i, n) for(int i = 0;i<n;i++)
#define kloop(i, k, n) for(int i=k;i<n;i++)
#define rloop(i, n) for(int i = n;i>=0;i--)
#define rkloop(i, n, k) for(int i = n;i>=k;i--)
#define MOD 1000000007
#define PI 3.14159265
const int MAXN = 100005;
typedef long long ll;
int fact[5001];
int invfact[5001];
int inv(int a, int b){
    if(b==0)
        return 1;
    if(b&1)
        return (long long)a*inv(a, b-1)%MOD;
    else{
        int res = inv(a, b>>1);
        return (long long)res*res%MOD;
    }
}
void init(){
    fact[0] = 1;
    for(int i=1;i<5001;i++){
        fact[i] = (long long)fact[i-1]*i%MOD;
    }
    invfact[5000] = inv(fact[5000], MOD-2);
    for(int i=5000;i>0;i--){
        invfact[i-1] = (long long)invfact[i]*i%MOD;
    }
}
int C(int n, int r){
    if(r>n || r<0)
        return 0;
    return (long long)((long long)fact[n]*invfact[r]%MOD)*invfact[n-r]%MOD;
}
int gcd(int a, int b){
    return a>b?(gcd(b, a)):(a==0?b:gcd(b%a, a));
}
void solve(){
    int n, x[15], y[15];
    cin>>n;
    if(n==1){
        cin>>x[0]>>y[0];
        cout<<"YES";
        return;
    }
    for(int i=0;i<n;i++){
        cin>>x[i]>>y[i];
    }
    int flag = 0;
    for(int i=1;i<n;i++){
        if(x[i]!=x[i-1]){
            flag=1;
            break;
        }
    }
    if(!flag){
        cout<<"YES";
        return;
    }
    for(int i=1;i<n;i++){
        if(y[i]!=y[i-1]){
            cout<<"NO";
            return;
        }
    }
    cout<<"YES";
}
int main(){
    solve();
    return 0;
}