#include <bits/stdc++.h>

using namespace std;

#define mt(a,x,b) memset(a,x,sizeof a)
#define mem(a) memset(a,0,sizeof a)
#define lp(i,n)  for(i=0;i<n;i++)
#define lpp(x,a,b) for(x=a;x<=b;x++)
#define pb push_back
#define prr pair<int,int>
#define imn INT_MAX
#define imx INT_MIN
#define sc scanf
#define pt(tc)  printf("Case %d: ",tc++)
#define ptt(tc)  printf("Case %d:\n",tc++)
#define pf printf
#define op(n) cout<<n<<endl
#define eps 1.e-9
#define ff first
#define ss second
#define ll long long
#define wh(t)  while(t--)
#define ug unsigned
#define fin  freopen("input.txt","r",stdin)
#define fout  freopen("output.txt","w",stdout)

//template<class T> inline T on(T n, T pos){return n | (1<<pos);}
//template <class T> inline T check(T n, T pos){return (bool)  n&(1<<pos);}
//template<class T> inline T gcd(T a, T b){if(b==0)return a ;else return gcd(b,a%b);}
//template <class T> inline T bigmod(T p,T e,T M){ll ret = 1;for(; e > 0; e >>= 1){if(e & 1) ret = (ret * p) % M;p = (p * p) % M;}return (T)ret;}
//template <class T> inline T modinverse(T a,T M){return bigmod(a,M-2,M);}
//template<class T> inline T lcm(T a, T b) {return a*b/gcd(a,b);}
//template<class T> inline T diff(T x2,T x1, T y2 ,T y1  ){double x ,y; x=((x2-x1)*(x2-x1)); y = ((y2-y1)*(y2-y1));return sqrt(x+y);}
//int dx[]={1,1,0,-1,-1,-1,0,1};int dy[]={0,1,1,1,0,-1,-1,-1};
//int dxh[]={2,1,-1,-2,-2,-1,1,2};int dyh[]={1,2,2,1,-1,-2,-2,-1};
//int toInt(string s){int sm;stringstream ss(s);ss>>sm;return sm;}
//int toLlint(string s){long long int sm;stringstream ss(s);ss>>sm;return sm;}
//string toStr(int number) {string Str; ostringstream convert; convert<< number;Str = convert.str(); }

int n;
set<int> st1,st2;
int main()
{

     int i,j,t,tc=1,a,b;
     sc("%d ",&n);
     lp(i,n)
     {
         sc("%d %d",&a,&b);
         st1.insert(a),st2.insert(b);
     }
     if(st1.size()==1||st2.size()==1)
        pf("YES\n");
     else
        pf("NO\n");


    return 0;
}