// بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ
// Written by Ilia Rahbar
#pragma GCC optimize ("O3,no-stack-protector,unroll-loops,fast-math")
#pragma GCC target ("abm,bmi,bmi2,tbm,avx2")
#include <bits/stdc++.h>
using namespace std;
#define int int64_t
#define ai(x) array <int, x>
#define F first
#define S second
const int MOD = 1e9 + 7, N = 1e5 + 100;
ai(2) a[N];
int n, l[N * 2], vs[N], ans = 1, cv[N];
struct DSU
{
vector <int> v[N];
int t[N];
bool d[N];
DSU(int x)
{
for (int i = 1; i <= x; i++)
{
v[i].push_back(i);
t[i] = i;
d[i] = 0;
}
}
bool mr(int x, int y)
{
if (t[x] == t[y])
{
if (d[x] == d[y])
{
cout << 0;
exit(0);
}
return 0;
}
if (v[t[x]].size() < v[t[y]].size())
swap(x, y);
bool nt = (d[x] == d[y]);
for (auto i : v[t[y]])
{
t[i] = t[x];
v[t[x]].push_back(i);
if (nt)
d[i] = !d[i];
}
return 1;
}
};
int32_t main()
{
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 0; i < n; i++)
cin >> a[i][0] >> a[i][1];
sort(a, a+n);
for (int i = 0; i < n; i++)
{
l[a[i][0]] = i+1;
l[a[i][1]] = i+1;
}
DSU d(n);
for (int i = 1; i <= n * 2; i++)
{
if (vs[l[i]])
{
for (int j = n; j > l[i]; j--)
{
if (vs[j] == 1)
{
d.mr(j, l[i]);
}
}
vs[l[i]] = 2;
}
else
vs[l[i]] = 1;
}
for (int i = 1; i <= n; i++)
{
if (!cv[d.t[i]])
{
ans = (ans * 2) % MOD;
cv[d.t[i]] = 1;
}
}
cout << ans;
}
