#include <bits/stdc++.h>

#define sq(n) ((n)*(n))
#define pf printf
#define sf scanf
#define INF 2000000000
#define pi (acos(-1.0))
#define i64 long long int
#define eps (1e-15)
#define DBG printf("Hi\n")
#define loop(i,n) for(i=1;i<=n;i++)
#define mod 1000000007
#define maxn 100005
#define ff first
#define ss second
#define mp(a,b) make_pair(a,b)
#define pb push_back
#define pii pair< int , int >
#define si(a) scanf("%d",&a)

using namespace std ;

int x[15], y[15] ;

int main()
{
    int i , j , k , l , m , n , fl1 = 1 , fl2 = 1 ;

    sf("%d",&n) ;

    for(i=1 ; i<=n ; i++) sf("%d %d",&x[i],&y[i]) ;

    for(i=2 ; i<=n ; i++)
    {
        if( x[i]!=x[1] ) fl1 = 0 ;
        if( y[i]!=y[1] ) fl2 = 0 ;
    }

    if(fl1||fl2) pf("YES\n") ;
    else pf("NO\n") ;

    return 0 ;
}