/*
* In the name of God
*
* Author: Farbod Doost
* Last Modified: Sun, 06 Nov 2022 (12:21:23)
*
*/
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
const int N = 2005, mod = 1e9 + 7;
int n, l[N], r[N];
vector <int> adj[N];
int d[N];
queue <int> q;
long long p(int a, int r)
{
if (r == 0)
return 1;
if (r == 1)
return a;
long long c = p(a, r / 2);
return c * c % mod * p(a, r % 2) % mod;
}
bool f(int i, int j)
{
if (l[i] < l[j] && l[j] < r[i] && r[i] < r[j])
return 1;
if (l[j] < l[i] && l[i] < r[j] && r[j] < r[i])
return 1;
return 0;
}
void bfs(int v)
{
d[v] = 0, q.push(v);
while (!q.empty()) {
int u = q.front();
q.pop();
for (auto x: adj[u]) {
if (d[x] == -1)
d[x] = d[u] + 1, q.push(x);
else if (d[x] == d[u]) {
cout << 0;
exit(0);
}
}
}
return;
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 0; i < n; i++)
cin >> l[i] >> r[i];
for (int i = 0; i < n; i++)
for (int j = i + 1; j < n; j++)
if (f(i, j))
adj[i].push_back(j),
adj[j].push_back(i);
for (int i = 0; i < n; i++)
d[i] = -1;
int ans = 0;
for (int i = 0; i < n; i++) {
if (d[i] != -1)
continue;
bfs(i), ans++;
}
cout << p(2, ans);
return 0;
}
