#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define ll long long
const int N=1e6+50,mod=1e9+7,lg=20;
bool test=false;
mt19937 rng(time(0));
int n,ev[2*N],L[N],R[N];
ll Brute(){
for(int i=1;i<=n;i++)ev[L[i]]=i,ev[R[i]]=-i;
ll res=0;
for(int mask=0;mask<1<<n;mask++){
vector<int>a[2];bool moze=true;
for(int i=1;i<=2*n;i++){
int j=abs(ev[i]);
if(ev[i]>0){
a[mask>>(j-1)&1].pb(j);
}
else{
if(a[mask>>(j-1)&1].empty()||a[mask>>(j-1)&1].back()!=j){moze=false;break;}
a[mask>>(j-1)&1].pop_back();
}
}
res+=moze;
}
return res;
}
struct Graph{
int to[4*N*lg],head[2*N*lg],nxt[4*N*lg],nc;
void Edge(int u,int v){
++nc;
to[nc]=v;
nxt[nc]=head[u];
head[u]=nc;
}
vector<int>adj(int u){
vector<int>temp;
for(int i=head[u];i>0;i=nxt[i])temp.pb(to[i]);
return temp;
}
}G;
//vector<int>E[2*N*lg];
int root1,root2,nc,lc[2*N*lg],rc[2*N*lg];
void Update(int &c1,int C1,int &c2,int C2,int ss,int se,int qind){
c1=++nc;lc[c1]=lc[C1],rc[c1]=rc[C1];
c2=++nc;lc[c2]=lc[C2];rc[c2]=rc[C2];
if(ss==se){
c2=c1;nc--;
//printf("c1 %i: [%i %i]\n",c1,ss,se);
//printf("c2 %i: [%i %i]\n",c2,ss,se);
return;
}
//printf("c1 %i: [%i %i]\n",c1,ss,se);
//printf("c2 %i: [%i %i]\n",c2,ss,se);
int mid=ss+se>>1;
if(qind<=mid)Update(lc[c1],lc[C1],lc[c2],lc[C2],ss,mid,qind);
else Update(rc[c1],rc[C1],rc[c2],rc[C2],mid+1,se,qind);
/*if(lc[c1])E[c1].pb(lc[c1]<<1);
if(rc[c1])E[c1].pb(rc[c1]<<1);
if(lc[c2])E[lc[c2]].pb(c2<<1);
if(rc[c2])E[rc[c2]].pb(c2<<1);*/
if(lc[c1])G.Edge(c1,lc[c1]<<1);
if(rc[c1])G.Edge(c1,rc[c1]<<1);
if(lc[c2])G.Edge(lc[c2],c2<<1);
if(rc[c2])G.Edge(rc[c2],c2<<1);
}
void Add(int c1,int c2,int ss,int se,int qs,int qe,int u){
if(c1==0||c2==0||qs>qe||qe<ss||se<qs)return;
if(qs<=ss&&se<=qe){
/*E[u].pb((c1<<1)^1);
E[c2].pb((u<<1)^1);*/
G.Edge(u,(c1<<1)^1);
G.Edge(c2,(u<<1)^1);
return;
}
int mid=ss+se>>1;
if(qe<mid+1)Add(lc[c1],lc[c2],ss,mid,qs,qe,u);
else if(mid<qs)Add(rc[c1],rc[c2],mid+1,se,qs,qe,u);
else Add(lc[c1],lc[c2],ss,mid,qs,qe,u),Add(rc[c1],rc[c2],mid+1,se,qs,qe,u);
}
bool was[2][2*N*lg];
/*void DFS(int u,bool col=0){
//cerr<<"vtx: "<<u<<" "<<col<<"\n";
was[col][u]=true;
for(auto i:E[u]){
if(!was[col^(i&1)][i>>1])DFS(i>>1,col^(i&1));
//if(was[i]&&col^bit!=Col[i]){bip=false;cerr<<u<<"<->"<<i<<"\n";}
//if(!was[i])bip=min(bip,DFS(i,col^bit));
}
//cerr<<u<<"- "<<col<<"\n";
}*/
void BFS(int U,bool col=0){
vector<int>kju;kju.pb(U<<1);
while(!kju.empty()){
int u=kju.back();kju.pop_back();
was[u&1][u>>1]=true;
for(auto i:G.adj(u>>1))if(!was[(u&1)^(i&1)][i>>1])kju.pb(((i>>1)<<1)^(u&1)^(i&1));
}
}
int idx[N],L1[N],R1[N];
ll Solve(){
for(int i=1;i<=n;i++)ev[L[i]]=i,ev[R[i]]=-i;
for(int i=1,cnt=-1;i<=2*n;i++){
int j=abs(ev[i]);
if(ev[i]>0) L1[j]=cnt;
else R1[j]=++cnt;
}
ll res=1;
for(int i=1;i<=2*n;i++)if(ev[i]>0){
int j=ev[i];
Update(root1,root1,root2,root2,0,n-1,R1[j]);
idx[j]=nc;
Add(root1,root2,0,n-1,L1[j]+1,R1[j]-1,nc);
}
//for(int i=1;i<=n;i++)printf("leaf %i: %i\n",i,idx[i]);
//for(int i=1;i<=nc;i++){printf("%i: ",i);for(auto [j,bit]:E[i])printf("[%i %i] ",j,bit?1:0);printf("\n");}
for(int i=1;i<=n;i++)if(!was[0][idx[i]]&&!was[1][idx[i]]){
BFS(idx[i]);
if(was[0][idx[i]]&&was[1][idx[i]]){res=0;break;}
res=(res<<1)%mod;
}
/*for(int i=0;i<=nc;i++){
was[0][i]=was[1][i]=lc[i]=rc[i]=0;
idx[i]=L1[i]=R1[i]=0;
E[i].clear();
}
root1=root2=nc=0;*/
return res;
}
int main(){
if(!test){
scanf("%i",&n);
for(int i=1;i<=n;i++){
int x,y;scanf("%i%i",&x,&y);
L[i]=x,R[i]=y;
}
ll res=Solve();
printf("%lld\n",res);
}
else{
int CT=0;
while(++CT){
if(CT%100==1)cerr<<"radi\n";
n=10;
vector<int>temp(2*n);iota(temp.begin(),temp.end(),1);
shuffle(temp.begin(),temp.end(),rng);
for(int i=0,j=1;i<2*n;i+=2,j++){
L[j]=temp[i],R[j]=temp[i+1];
if(L[j]>R[j])swap(L[j],R[j]);
}
ll x=Brute(),y=Solve();
if(x!=y){
printf("%i\n",n);
for(int i=1;i<=n;i++)printf("%i %i\n",L[i],R[i]);
printf("\n%lld %lld\n",x,y);
return 0;
}
}
}
return 0;
}
