#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{
    int n,x,y,f1,f2,a,b,z1,z2,i;
    while(scanf("%d",&n)!=EOF)
    {
        f1=0;f2=0;z1=0,z2=0;
        for (i=1;i<=n;i++)
        {

            cin>>x>>y;
            if (i>1)
            {
                if (x==a   && z1==0)
                    f1=1;
                else
                {
                    f1=0;
                    z1=1;
                }

                if (y==b && z2==0)
                    f2=1;
                else
                {
                    f2=0;
                    z2=1;
                }

            }
            a=x;
            b=y;


        }
        if (f1==1 || f2==1)
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
}