#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll MOD=1e9+7;
const int LIM=1e6+7;
vector<pair<int,int>>V[LIM];
ll ans=1;
pair<int,int>T[LIM];
int kol[LIM], tr[8*LIM], kto[8*LIM], trmi[8*LIM], N=1;
void DFS(int x, int o) {
for(auto i : V[x]) {
if(!kol[i.st]) {
kol[i.st]=kol[x]^i.nd;
DFS(i.st, x);
} else if((kol[i.st]^i.nd)!=kol[x]) ans=0;
}
}
void dodaj(int a, int b) {
if(b==-1) return;
if(T[b].st<T[a].st) {
V[a].pb({b, 3});
V[b].pb({a, 3});
}
}
void upd(int l, int r, int x, int a) {
if(l>r) return;
l+=N; r+=N;
tr[l]=max(tr[l], x);
dodaj(a, trmi[l]);
tr[r]=max(tr[r], x);
dodaj(a, trmi[r]);
while(l/2!=r/2) {
if(l%2==0) {
tr[l+1]=max(tr[l+1], x);
dodaj(a, trmi[l+1]);
}
if(r%2==1) {
tr[r-1]=max(tr[r-1], x);
dodaj(a, trmi[r-1]);
}
l/=2; r/=2;
}
}
vector<pair<int,int>>zejdz(int v, int a, int b) {
trmi[v]=-1;
if(a==b) {
if(kto[a]==-1) return {};
trmi[v]=kto[a];
return {{T[kto[a]].st, kto[a]}};
}
int mid=(a+b)/2;
vector<pair<int,int>>A=zejdz(2*v, a, mid), B=zejdz(2*v+1, mid+1, b);
vector<pair<int,int>>C;
int l=0;
for(auto i : A) {
while(l<B.size() && B[l]<=i) C.pb(B[l++]);
C.pb(i);
}
while(l<B.size()) C.pb(B[l++]);
l=0;
while(l+1<C.size() && C[l+1].st<=tr[v]) {
V[C[l].nd].pb({C[l+1].nd, 0});
V[C[l+1].nd].pb({C[l].nd, 0});
++l;
}
if(C.size()) trmi[v]=C[0].nd; else trmi[v]=-1;
return C;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int n;
cin >> n;
while(N<2*n) N*=2;
rep(i, 2*N) tr[i]=-MOD;
rep(i, N) kto[i]=-1;
rep(i, n) {
cin >> T[i].st >> T[i].nd;
--T[i].st; --T[i].nd;
}
sort(T, T+n);
rep(i, n) kto[T[i].nd]=i;
zejdz(1, 0, N-1);
rep(i, n) upd(T[i].st+1, T[i].nd-1, T[i].st-1, i);
zejdz(1, 0, N-1);
rep(i, n) if(!kol[i]) {
kol[i]=1;
DFS(i, i);
ans=(ans*2)%MOD;
}
cout << ans << '\n';
}
