#include <bits/stdc++.h>
using namespace std;


typedef long long int LL;
typedef unsigned long long LLU;
typedef long double LD;

#define INF 1110000000000000000LL
#define MOD 1000000007
#define F first
#define S second
#define PB push_back
#define MK make_pair
#define PP pop_back
#define LEN(vale) strlen(vale)
#define SZ(vale) (int)vale.size()
#define SQ(A) ((A)*(A))
#define pc putchar_unlocked
#define gc getchar_unlocked
#define FI(i12,fa,fb) for(int i12=fa;i12<fb;++i12)
#define FD(i12,fa,fb) for(int i12=fa;i12>fb;--i12)
#define FT(it,S) for(it = (S).begin(); it != (S).end(); ++it) 
#define bits(vale) __builtin_popcount(vale)
#define VT vector

#define SET1(array,val,sz) for(int i13=0;i13<sz;i13++)array[i13]=val;
#define SET2(array,val,sz1,sz2) for(int i13=0;i13<sz1;i13++)for(int i14=0;i14<sz2;i14++)array[i13][i14]=val;

#define ALL(a) a.begin(),a.end()
#define LB (lower_bound)
#define UB (upper_bound)

#define SI(vale) scanf("%d",&vale)
#define PI(vale) printf("%d\n",vale)
#define PIS(vale) printf("%d ",vale)
#define SL(vale) scanf("%lld",&vale)
#define PL(vale) printf("%lld\n",vale)
#define PLS(vale) printf("%lld ",vale)
#define SS(vale) scanf("%s",vale)
#define PS(vale) printf("%s\n",vale)
#define SLD(vale) scanf("%Lf",&vale)
#define PLD(vale) printf("%0.12Lf\n",vale)
#define NL printf("\n")
#define TCS() int testcase; SI(testcase);while(testcase--) 

typedef pair<int,int> PR;
bool deb = false;
const int N = 100011;
PR a[N];

int main(){
     //clock_t tStart = clock();
     int n;
     //TCS(){
     SI(n);
     FI(i,0,n) SI(a[i].F),SI(a[i].S);
     bool ok = 1;
     FI(i,1,n) {
          if(a[i-1].F == a[i].F)
               int j;
          else
               ok = 0;
     }
     bool ok2 = 1;
     if(!ok) {
          FI(i,1,n) {
               if(a[i-1].S == a[i].S)
                    int j;
               else
                    ok2 = 0;
          }
     }
     if(!ok && !ok2) puts("NO");
     else
          puts("YES");



     //exectime();
     return 0;        
}