#include <bits/stdc++.h>
#include<ext/pb_ds/priority_queue.hpp>
#define jizz ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define pb push_back
#define MP make_pair
#define F first
#define S second
#define MEM(i,j) memset(i,j,sizeof i)
#define ALL(v) v.begin(),v.end()
#define ET cout << "\n"
#define DB(a,s,e) {for(int i=s;i<e;++i) cout << a[i] << " ";ET;}
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
__gnu_pbds::priority_queue<pii,greater<pii>,pairing_heap_tag> pq[1000005];
map<int,int> mp;
pii seg[1000005];
int boss[2000005];
bitset<2000005> vis;
int finds(int x)
{
if(boss[x]==x) return x;
return boss[x]=finds(boss[x]);
}
void Union(int a,int b)
{
a=finds(a),b=finds(b);
boss[a]=b;
}
void merge(int a,int b,int t)
{
if(t==0)
Union(a<<1,b<<1),Union(a<<1|1,b<<1|1);
else
Union(a<<1,b<<1|1),Union(a<<1|1,b<<1);
}
int main()
{jizz
int n,flag=1,ans=1,cnt=0,tp=0;
cin >> n;
for(int i=0;i<n;++i)
cin >> seg[i].F >> seg[i].S,boss[i<<1]=i<<1,boss[i<<1|1]=i<<1|1;
sort(seg,seg+n);
for(int i=0;i<n&&flag;++i)
{
while(!mp.empty()&&mp.begin()->F<seg[i].F)
{
int t=mp.begin()->S;
mp.erase(mp.begin()),pq[t].pop();
if(!pq[t].empty())
mp.insert(MP(pq[t].top().F,t));
}
int beg=-1;
while(!mp.empty()&&mp.begin()->F<seg[i].S)
{
if(!~beg) beg=mp.begin()->S;
else merge(pq[beg].top().S,pq[mp.begin()->S].top().S,0),pq[beg].join(pq[mp.begin()->S]);
mp.erase(mp.begin());
}
if(~beg)
merge(i,pq[beg].top().S,1),mp.insert(MP(pq[beg].top().F,beg));
pq[tp].push(MP(seg[i].S,i)),mp.insert(MP(seg[i].S,tp)),++tp;
}
for(int i=0;i<n&&flag;++i)
if(finds(i<<1)==finds(i<<1|1))
flag=0;
else
{
if(!vis[finds(i<<1)]) ++cnt,vis[finds(i<<1)]=1;
if(!vis[finds(i<<1|1)]) ++cnt,vis[finds(i<<1|1)]=1;
}
cnt/=2;
for(int i=0;i<cnt;++i)
ans=ans*2%MOD;
if(flag) cout << ans << "\n";
else cout << "0\n";
}
