#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned ll
#define ld long double
#define ff first
#define ss second
#define ln "\n"
const ll MOD = 1e9+7;
void dfs(ll u, vector<ll> &vis, vector<vector<ll>> &A){
vis[u]=1;
for (auto v:A[u]){
if (vis[v]) continue;
dfs(v, vis, A);
}
}
void solve(){
ll n; cin >> n;
vector<ll> a(2*n+1);
vector<array<ll, 2>> rng(n);
for (ll i=0; i<n; i++){
ll l, r; cin >> l >> r;
a[l]=i; a[r]=i; rng[i] = {l, r};
}
vector<vector<ll>> A(n);
set<array<ll, 2>> present;
vector<ll> col(n, -1);
for (ll i=1; i<=2*n; i++){
// for (auto ch:present) cout << ch << " ";
// cout << ln;
if (!present.count({rng[a[i]][1], a[i]})){
for (auto [r, ind]:present){
if (r>rng[a[i]][1]) break;
if (col[ind]==-1) {
if (col[a[i]]==-1){
col[ind]=1; col[a[i]]=0;
}else col[ind]=col[a[i]]^1;
}else{
if (col[a[i]]==-1) col[a[i]]=col[ind]^1;
else if (col[a[i]]==col[ind]){
cout << 0 << ln; return;
}
}
A[ind].push_back(a[i]); A[a[i]].push_back(ind);
}
present.insert({rng[a[i]][1], a[i]});
}else{
present.erase({rng[a[i]][1], a[i]});
}
}
ll res=1; vector<ll> vis(n);
for (ll i=0; i<n; i++){
if (!vis[i]) dfs(i, vis, A), res=(res*2)%MOD;
}
cout << res << ln;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(nullptr);
ll t=1;
// cin >> t;
while (t--) solve();
}
