#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=2e6+5;
const ld pi=3.14159265359;
const ll INF=(1LL<<60);
#define SQ(i) ((i)*(i))
#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()
map<pll,ll> col;
ll seg[3][4*N],ans=1,n,x,y;
ll r[N],l[N];
set<ll> idx;
vector<pll> ed;
ll Q(ll ty,ll id,ll l,ll r,ll ql,ll qr){
if(l>=ql&&r<=qr)return seg[ty][id];
if(l>=qr||r<=ql)return 0;
ll mid=(l+r)/2;
return Q(ty,id*2,l,mid,ql,qr)+Q(ty,id*2+1,mid,r,ql,qr);
}
void ins(ll ty,ll id,ll l,ll r,ll to,ll d){
if(l==r-1){seg[ty][id]+=d;return;}
ll mid=(l+r)/2;
if(to<mid){
ins(ty,id*2,l,mid,to,d);
}else{
ins(ty,id*2+1,mid,r,to,d);
}
seg[ty][id]=seg[ty][id*2]+seg[ty][id*2+1];
}
void DFS(pll nd){
for(ll i=*idx.lwb(nd.X);i<nd.Y;i=*idx.lwb(i+1)){
pll tmp;
if(l[i]&&l[i]<nd.X)tmp=mp(l[i],i);
if(r[i]&&r[i]>nd.Y)tmp=mp(i,r[i]);
col[tmp]=3-col[nd];
idx.erase(tmp.X);idx.erase(tmp.Y);
DFS(tmp);
}
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n;
idx.insert(2*n+1);idx.insert(0);
REP1(i,n)cin>>x>>y,ed.pb(mp(x,y)),r[x]=y,l[y]=x,idx.insert(x),idx.insert(y);
sort(ed.begin(),ed.end(),[](pll a,pll b){
if(a.Y-a.X!=b.Y-b.X)return (a.Y-a.X<b.Y-b.X);
return (a.X<b.X);
});
for(auto i:ed){
if(!col[i]){
ans=ans*2%MOD;
col[i]=1;
idx.erase(i.X);idx.erase(i.Y);
DFS(i);
}
}
sort(ed.begin(),ed.end());
for(auto i:ed){
int ty=col[i];
if(Q(ty,1,1,2*n+1,i.X,i.Y+1)){
cout<<"0\n";return 0;
}
ins(ty,1,1,2*n+1,i.Y,1);
}
cout<<ans<<"\n";
return 0;
}
