#include <bits/stdc++.h>
using namespace std;
#define foru(i,a,b) for(int i=(a); i<=(b); ++i)
#define ford(i,a,b) for(int i=(a); i>=(b); --i)
#define rep(i,a) for(int i=0; i<(a); ++i)
#define bit(s,i) (((s)>>(i))&1)
#define all(a) (a).begin(),(a).end()
#define sz(a) (int)(a).size()
#define ii pair<int,int>
#define fi first
#define se second
#define eb emplace_back
#define pb push_back
#define ll long long
#define __builtin_popcount(a) __builtin_popcountll(a)
template <class X, class Y> bool maxi(X &x, Y y){return x<y?x=y,true:false;}
template <class X, class Y> bool mini(X &x, Y y){return x>y?x=y,true:false;}
const int N=2e6+5;
const int mod=1e9+7;
int n; ii cont[N];
ii st[N<<2];
void upd(int x, ii val){
int id=1, l=1, r=2*n;
while(l<r){
int mid=(l+r)>>1;
if(x<=mid){
r=mid;
id=id<<1;
} else{
l=mid+1;
id=id<<1|1;
}
}
st[id]=val;
while(id>1){
id/=2;
st[id]=max(st[id<<1], st[id<<1|1]);
}
}
ii get(int u, int v, int id=1, int l=1, int r=2*n){
if(u>r||v<l) return {0,0};
if(u<=l&&r<=v) return st[id];
int mid=(l+r)>>1;
return max(get(u,v,id<<1,l,mid), get(u,v,id<<1|1,mid+1,r));
}
int stk[N],top;
int num[N],ncc;
bool vis[N];
vector<int> hihi[2];
void dfs(int u){
vis[u]=true;
hihi[num[u]].eb(u);
upd(cont[u].fi,{0,0});
while(true){
ii tmp=get(cont[u].fi+1,cont[u].se-1);
if(tmp.fi<cont[u].se) break;
num[tmp.se]=num[u]^1;
dfs(tmp.se);
}
}
void solve(){
cin>>n;
foru(i,1,n) cin>>cont[i].fi>>cont[i].se;
sort(cont+1, cont+1+n);
foru(i,1,n){
upd(cont[i].fi, {cont[i].se, i});
}
int res=1;
foru(i,1,n) if(!vis[i]){
++ncc;
dfs(i);
foru(j,0,1){
sort(all(hihi[j]));
top=0;
for(int k:hihi[j]){
while(top && cont[stk[top]].se<cont[k].fi) --top;
if(top && cont[k].se>cont[stk[top]].se){
cout<<"0\n";
return;
}
stk[++top]=k;
}
hihi[j].clear();
}
res=res+res;
if(res>=mod) res-=mod;
}
cout<<res<<'\n';
}
int32_t main(){
#define task "test"
if(fopen(task".inp","r")){
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
cin.tie(0)->sync_with_stdio(0);
solve();
}
