/* Have courage and be kind*/
#include<bits/stdc++.h>
#include<stdlib.h>
#include <assert.h>  //assert ( n >= 1 && n < 100005 );
using namespace std;
#define inf 2147383647LL
#define SET(a) memset(a,-1,sizeof(a))
#define all(a) a.begin(),a.end()
#define CLR(a) memset(a,0,sizeof(a))
#define PB push_back
#define MP make_pair
#define pii pair<int,int>
#define FOR0(i,n) for(int i = 0;i<n;i++)
#define FOR1(i,n) for(int i = 1;i<=n;i++)
#define MIN(a,b) ((a)<(b)?(a):(b))
#define MAX(a,b) ((a)>(b)?(a):(b))
#define PI acos(-1.0)
#define EPS 1e-9
#define UNIQUE(V) (V).erase(unique((V).begin(),(V).end()),(V).end())//vector must be sorted
#define NUMDIGIT(x,y) (((int)(log10((x))/log10((y))))+1)
#define LCM(x,y) (((x)/gcd((x),(y)))*(y))
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
#define lol long long
#define ulol unsigned long long
#define pf printf
#define sf scanf
#define mod 1000000007 //10^9+7
#define pause system("pause")
#define F first
#define S second
#define phl printf ( "hello\n" )
#define POPCOUNT __builtin_popcountll
#define RIGHTMOST __builtin_ctzll
#define LEFTMOST(x) (63-__builtin_clzll((x)))

lol mod_v(lol num)
{
    if(num>=0)
      return(num%mod);
    else
     return(num%mod+mod)%mod;
}

lol bigmod ( lol b, lol p, lol m ) {  //Repeated Squaring Method for Modular Exponentiation
    lol res = 1 % m, x = b % m;
    while ( p ) {
        if ( p & 1 ) res = ( res * x ) % m;
        x = ( x * x ) % m;
        p >>= 1;
    }
    return res;
}

/********** Solution ***************/
set<int>stx;
set<int>sty;
int main()
{
    //READ("input.txt");
    int n , x, y;

    sf("%d", &n);

    FOR1(i, n)
    {
        sf("%d %d", &x, &y);
        stx.insert(x);
        sty.insert(y);
    }

    if(stx.size() == 1 || sty.size() == 1)
     pf("YES\n");
    else
    pf("NO\n");
}