#include<bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	ll n;
	cin>>n;
	bool ans=0;
	for(int i=0;i<n;i++){
		ll a,b;
		cin>>a>>b;
		if(a==1)ans=1;
	}
	if(ans) cout<<"Yes"<<endl;
	else cout<<"No"<<endl;
}