#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod=1000000007;
const int MAXN=1000010, LOG=20;
int n, m, k, u, v, x, y, t, a, b, ans;
int A[MAXN], B[MAXN];
int L[MAXN], R[MAXN];
int par[MAXN], parx[MAXN];
int seg[MAXN<<3], sz[MAXN<<3];
pii getpar(int x){
if (par[x]==x) return {x, 0};
pii p=getpar(par[x]);
par[x]=p.first;
parx[x]^=p.second;
return {par[x], parx[x]};
}
int join(int x, int y, int w){
// debug2(x, y)
pii xx=getpar(x);
pii yy=getpar(y);
if (xx.first!=yy.first){
par[xx.first]=yy.first;
parx[xx.first]=xx.second^yy.second^w;
ans--;
return 1;
}
if (xx.second^yy.second^w){
cout<<"0\n";
exit(0);
}
return 0;
}
void Set(int id, int tl, int tr, int pos, int x){
if (pos<tl || tr<=pos) return ;
if (tr-tl==1){
seg[id]=x;
sz[id]=1;
return ;
}
int mid=(tl+tr)>>1;
Set(id<<1, tl, mid, pos, x);
Set(id<<1 | 1, mid, tr, pos, x);
sz[id]=sz[id<<1]+sz[id<<1 | 1];
seg[id]=0;
}
void Merge(int id, int tl, int tr, int l, int r, int x){
if (r<=tl || tr<=l || !sz[id]) return ;
if (l<=tl && tr<=r && seg[id]){
join(x, seg[id], 1);
return ;
}
int mid=(tl+tr)>>1;
Merge(id<<1, tl, mid, l, r, x);
Merge(id<<1 | 1, mid, tr, l, r, x);
if (l<=tl && tr<=r && tr-tl>1) seg[id]=seg[id<<1];
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin>>n;
for (int i=1; i<=n; i++){
cin>>L[i]>>R[i];
B[L[i]]=i;
B[R[i]]=-i;
par[i]=i;
}
ans=n;
for (int i=1; i<=2*n; i++) if (B[i]>0){
int x=B[i];
Set(1, 1, 2*n+1, R[x], x);
Merge(1, 1, 2*n+1, L[x], R[x], x);
}
ll res=1;
while (ans--) res=res*2%mod;
cout<<res<<"\n";
return 0;
}
