#include<bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define FOR(i,a,n) for(i=a;i<=n;++i)
#define RFOR(i,a,n) for(i=a;i>=n;--i)
#define ll long long
#define pll pair<long long , long long>
#define prr(a,b) pair< a , b >
#define vec(t) vector< t >
long long M = 1e9+7;
const ll INF = LLONG_MAX;

void build(long long init,long long l, long long r,ll* st,ll* ar, ll val, ll n)
{


if(l!=r)
{
build(2*init+1,l,(l+r)/2,st,ar,val,n);
build(2*init+2,(l+r)/2+1,r,st,ar,val,n);

st[init] = st[2*init+1]*st[2*init+2];
if(st[init]>=10){st[init]=st[init]/10;}
//cout << st[init]<< " " << init << "yy\n";
}
else
{
	ll x = ar[l*val];
	while(x>0)
	{
	st[init] = x;
	x = x/10;	
	}
}



}


void modify(long long init,long long l,long long r,long long ind,ll x,ll *st)
{

if(l!=r)
{
if(ind<=(l+r)/2)
{
modify(2*init+1,l,(l+r)/2,ind,x,st);
}
else
{
modify(2*init+2,(l+r)/2+1,r,ind,x,st);
}

st[init] = st[2*init+1]*st[2*init+2];
if(st[init]>=10){st[init]=st[init]/10;}

}
else
{
//cout << l << "mod\n";
while(x>0)
{
st[init] = x;
x = x/10;	
}

}


}



ll getans(ll *st)
{

return st[0];

/*
if(r<ql || l>qr)
{
return;
}

ql = max(l,ql);
qr = min(r,qr);


if(l==ql && r==qr)
{
pll foo;
foo.first = max((*ans).first,st[init].first);
foo.second = 0;
foo.second = (foo.second+(st[init].second)*(foo.first==(st[init].first)))%M;
foo.second = (foo.second+((*ans).second)*(foo.first==((*ans).first)))%M;
(*ans) = foo;
cout << (*ans).second;
return;
}


getans(2*init+1,l,(l+r)/2,ql,qr,ans,st,L);
getans(2*init+2,(l+r)/2+1,r,ql,qr,ans,st,L);
*/



}



long long power_2(long long p1,long long p2,ll x = M)
{

if(p2==0){return 1;}
if(p2==1){return p1%x;}

long long y = power_2(p1,p2/2,x);
y = ((((y*y)%x)*power_2(p1,p2%2,x))%x);
return y;


}

long long inv(long long p1){return power_2(p1,M-2);}

long long fact(long long n)
{
ll i,nlt= 1;
FOR(i,1,n)
{
nlt = (nlt*i)%M;
}
return nlt;
}



bool check_pr(ll x,vec(ll)* pr)
{
ll n = (*pr).size();
ll i;

for(i = 0;i<n && ((*pr)[i])*((*pr)[i])<=x;++i)
{
if(x%((*pr)[i])==0)
{
return false;
}
}
return true;
}

pll inv(pll x)
{
	pll ans;
	ans.first =  x.second;
	ans.second =  x.first;
	return ans;
}

void fth(ll st, vec(set<ll>)* edges,bool *visited,ll *mx,ll dist,ll* vt)
{
	
	visited[st] = true;
set<ll>::iterator it;
*vt = ((*mx>=dist)?(*vt):st);
*mx = max(*mx,dist);
set<ll> x1 = (*edges)[st];
for(it = x1.begin();it!=x1.end();++it)
{
if(!visited[*it]){fth((*it),edges,visited,mx,dist+1,vt);}
}

	
	
}


void merge(ll* a, ll* b, ll* c,ll sz,ll x)
{
	ll i,j;
	ll *d=  new ll[x];fill(d,d+x,0);
	FOR(i,1,x)
	{
		FOR(j,1,x)
		{
			ll val = (((i-1)*power_2(10,sz,x))%x+(j-1))%x;
			d[val] = (d[val]+((a[(i-1)]*b[(j-1)])%M) )%M;			
		}		
	}
	
	FOR(i,1,x)
	{
		c[i-1] = (c[i-1]+d[i-1])%M;
	}
	
}


ll gcd(ll a,ll b)
{

if(a > b )
{return gcd(b,a);}


if(a==b || a==0)
{
return b;
}

return gcd(b%a,a);
}


int getans_2(double x)
{
	double fr = x-floor(x);
	int i = 1;
	//cout << fr << endl;
	while(true)
	{
			if(log10((double)(i+1))<=fr)
			{
				++i;
				continue;
			}
			return i;
		
	}
	//return (int)(floor(pow(10,fr)));
	
}

bool ans = true;

ll dfs(vec(set<ll>)* edges,ll* visited,ll* wish,ll* arr,ll h,ll st)
{
	visited[st] = h;
	ll mx = 1e6;
	set<ll>::iterator it;
//cout << st;
set<ll> x1 = (*edges)[st];
for(it = x1.begin();it!=x1.end();++it)
{
if(visited[(*it)]==-1)
{
ll mx_wh = dfs(edges,visited,wish,arr,h+1,*it);
mx = min(mx,mx_wh);
}

}
//cout << st;
if(mx<h && arr[st]!=0)
{
	ans = false;
}
return min(mx,visited[wish[st]]);
	
	
}
int main() {


vec(prr(ll,ll)) xx;
long long n,m,h,p,l,r,t1,q,z,a,b,c,sum = 0,mult = 1;
long long i,j,k;
string s,s1,s2;
double d,v,e,t,x,y;
t1 = 1;
//cin >> t1;
double pi = 3.14159265359;
a = 1e9*1e9;
//cout << 8*a+1;
ll sz = 1e5;

/*
ll *ans = new ll[sz];
double *ans_2 = new double[sz];
ll *arr = new ll[sz];
vec( vec(ll) ) divs(sz);
fill(arr,arr+sz,1);
*/
/*
ll **st = new ll*[sz];
FOR(i,1,sz)
{
	ll sz_i = ((sz-1)/i)+1;
	st[i-1] = new ll[4*sz_i];	
}
*/
sz = 1e2;
/*
ll* sg = new ll[sz+1];

vec(set <ll>)  vc(sz+1);
sg[1] = 0;

FOR(i,2,sz)
{
	vc[i].insert(0);
	set<ll>::iterator it;
	ll val = 0;
	for(it = vc[i].begin();it!=vc[i].end();++it)
	{
		if(*it==val)
		{
			++val;
		}
		else
		{
			break;
		}
		
	}
	sg[i] = val;
	//cout << val;
	for(j = 2*i;j<=sz;j = j+i)
	{
		vc[j].insert(sg[i]);
	}

}
*/


//cin >> t1;
while(t1-->0)
{
	cin >> n;
	ll mxx=-11,mxy = -11,mix=11,miy = 11;
	FOR(i,1,n)
	{
		cin >> j >> k;
		mxx = max(mxx,j);
		mix = min(mix,j);
		mxy = max(mxy,k);
		miy = min(miy,k);
		
	}
	cout << (((mxx==mix)||(mxy==miy))?"YES":"NO") << endl;
}


return 0;
}