#include<bits/stdc++.h>
#define rp(i,a,b) for(int i=a,_=b;i<=_;++i)
#define pr(i,a,b) for(int i=a,_=b;i>=_;--i)
#define pb push_back
using namespace std;
typedef vector<int> VI;
const int N=205;
int n,m,cnt[3*N],sum[3*N],bg[2*N],ed[2*N];
bool dp[2*N][3*N];
VI tmp;
struct range{
	int l,r,id;
	bool operator<(const range &o)const{return l<o.l||(l==o.l&&r<o.r);}
}a[2*N];
inline int get(int x){return lower_bound(tmp.begin(),tmp.end(),x)-tmp.begin()+1;}
int main(){
	scanf("%d",&n),n*=2;
	for(int i=1;i<=n;i+=2){
		scanf("%d%d",&a[i].l,&a[i+1].r);
		a[i].r=a[i+1].l=(a[i].l+a[i+1].r)>>1;
	}
	rp(i,1,n)a[i].id=i,tmp.pb(a[i].l),tmp.pb(a[i].r);
	sort(tmp.begin(),tmp.end());
	tmp.resize(unique(tmp.begin(),tmp.end())-tmp.begin());
	m=tmp.size();
	rp(i,1,n)++cnt[a[i].l=get(a[i].l)],--cnt[a[i].r=get(a[i].r)];
	rp(i,1,m)cnt[i]+=cnt[i-1];
	rp(i,1,m)sum[i]=sum[i-1]+((!cnt[i])!=(!cnt[i-1]));
	sort(a+1,a+n+1);
	bool ans=0;
	rp(i,1,n){
		bg[i]=cnt[a[i].l]&&!cnt[a[i].l-1]?sum[a[i].l]:-1;
		ed[i]=!cnt[a[i].r]&&cnt[a[i].r-1]?sum[a[i].r]:-1;
		if(bg[i]==1){
			dp[i][a[i].l]=1;
		}
		rp(k,a[i].l,a[i].r-1)if(dp[i][k]){
			rp(j,i+1,n)if(a[j].l>k&&a[j].l<=a[i].r&&a[j].r>a[i].r&&a[i].id!=a[j].id-1)dp[j][a[i].r]=1;
		}
		if(~ed[i]){
			bool b=0;
			rp(k,a[i].l,a[i].r-1)if(dp[i][k]){b=1;break;}
			if(!b)continue;
			if(ed[i]==sum[m])ans=1;
			rp(j,i+1,n)if(bg[j]==ed[i]+1)dp[j][a[j].l]=1;
		}
	}
	puts(ans?"YES":"NO");
	return 0;
}