#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <chrono>
#include <random>
#include <bitset>
#include <utility>
const int mod = 1e9 + 7;
int n;
int ans = 1;
int dsu[1000005], H[1000005], Rank[1000005];
int A[1000005], B[1000005];
int Event[2000005];
int Root(int node)
{
return dsu[node] == node ? node : dsu[node] = Root(dsu[node]);
}
void Union(int u, int v)
{
u = Root(u);
v = Root(v);
if(u != v)
{
if(Rank[u] > Rank[v])
{
std::swap(u, v);
}
dsu[v] = u;
if(Rank[u] == Rank[v])
{
Rank[u]++;
}
}
else
{
std::cout << 0;
exit(0);
}
}
int main()
{
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
std::cout.tie(0);
std::cin >> n;
for(int i = 1; i <= n; i++)
{
Rank[i] = 0;
dsu[i] = i;
std::cin >> A[i] >> B[i];
Event[A[i]] = i;
Event[B[i]] = -i;
}
std::set <std::pair <int, int> > S;
std::set <int> T;
for(int i = 1; i <= 2 * n; i++)
{
if(Event[i] > 0)
{
for(auto x : S)
{
if(x.first > B[Event[i]])
{
break;
}
Union(x.second, Event[i]);
}
S.insert(std::make_pair(B[Event[i]], Event[i]));
}
else
{
S.erase(std::make_pair(B[-Event[i]], -Event[i]));
}
}
for(int i = 1; i <= n; i++)
{
if(Root(i) == i)
{
ans = ans * 2;
if(ans >= mod)
{
ans -= mod;
}
}
}
std::cout << ans;
}
