#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,a,b,flag=0,x,y;
    cin>>n;
    cin>>a>>b;
    n--;
    int num=n;
    if(a==0){
    while(n--)
    {
       cin>>x>>y;
       if(x!=0)
        flag=1;
    }
    }
    n=num;
    if(b==0){
    while(n--)
    {
       cin>>x>>y;
       if(y!=0)
        flag=1;
    }
    }
    n=num;
    if(a!=0&&b!=0)
    {
        while(n--)
    {
       cin>>x>>y;
       flag=1;
    }
    }
    if(flag==0)cout<<"YES";
    else cout<<"NO";
}