#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n;
bool ans=true;
struct yyds{
	ll a;
	ll b;
}x[200005];
bool cmp(yyds awa,yyds qwq){
	return (awa.a<qwq.a);
}
int main(){
	ios::sync_with_stdio(false);
	cin>>n;
	for (ll i=1;i<=n;i++){
		cin>>x[i].a>>x[i].b;
		if (x[i].a>x[i].b) swap(x[i].a,x[i].b);
	}
	sort(x+1,x+n+1,cmp);
	for (ll i=1;i<n;i++){
		if ((x[i].a<x[i+1].a) && (x[i].b<x[i+1].b) && (x[i].b>x[i+1].a)){
			ans=false;
		}
	}
	if (!ans) cout<<"Yes";
	else cout<<"No";
	return 0;
}

WA1，AC30 Where is the problem?