#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll MOD=1e9+7;
const ll N=2e6+5;
const ld pi=3.14159265359;
const ll INF=(1LL<<62);
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(a) (ll)a.size()
ll seg[4*N],x,y,n;
vector<pll> v;
void ins(ll id,ll l,ll r,ll to,ll d){
if(r==l+1){seg[id]+=d;return ;}
ll mid=(l+r)/2;
if(to<mid){
ins(id*2,l,mid,to,d);
}else{
ins(id*2+1,mid,r,to,d);
}
seg[id]=seg[id*2]+seg[id*2+1];
}
ll SRC(ll id,ll l,ll r,ll ql,ll qr){
if(l>=ql&&r<=qr)return seg[id];
if(l>=qr||r<=ql)return 0;
ll mid=(l+r)/2;
return SRC(id*2,l,mid,ql,qr)+SRC(id*2+1,mid,r,ql,qr);
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n;
REP1(i,n){
cin>>x>>y;v.pb(mp(x,y));
}
ll ans=1;
sort(v.begin(),v.end());
for(auto i:v){
ll tmp=SRC(1,1,2*n+1,i.X,i.Y);
if(tmp<=1){
if(tmp==0)ans=(ans*2)%MOD;
ins(1,1,2*n+1,i.Y,1);
}else{
ans*=0;
}
}
for(auto &i:v){
ins(1,1,2*n+1,i.Y,-1);
i.X=2*n+1-i.X;i.Y=2*n+1-i.Y;
swap(i.X,i.Y);
}
sort(v.begin(),v.end());
for(auto i:v){
ll tmp=SRC(1,1,2*n+1,i.X,i.Y);
if(tmp<=1){
ins(1,1,2*n+1,i.Y,1);
}else{
ans*=0;
}
}
cout<<ans<<"\n";
return 0;
}
