#include <bits/stdc++.h>
#define N 3001
#define mod (1000000000 + 7)
#define f first
#define s second
using namespace std;
typedef pair<int, int> pii;
int n, ans, block[N][N], cor[N], qtd, pot[N];
pii v[N];
bool nope = false;
vector<int> grafo[N];
bool intersect(int i, int j)
{
if(v[j].f < v[i].f) swap(i, j);
if(v[i].f <= v[j].f && v[j].s <= v[i].s) return false;
if(v[i].f < v[j].f && v[j].f < v[i].s) return true;
return false;
}
void dfs_color(int x)
{
for(auto v: grafo[x])
{
if(cor[v] == cor[x])
{
nope = true;
return;
}
if(cor[v] != -1) continue;
cor[v] = (cor[x] + 1)%2;
dfs_color(v);
}
}
int main()
{
ios::sync_with_stdio(false); cin.tie(0);
cin>>n;
for(int i = 1; i <= n; i++) cin>>v[i].f>>v[i].s;
pot[0] = 1;
for(int i = 1; i <= n; i++) pot[i] = (2*pot[i - 1])%mod;
for(int i = 1; i <= n; i++)
{
for(int j = 1; j <= n; j++)
{
if(intersect(i, j))
{
grafo[i].push_back(j);
grafo[j].push_back(i);
}
}
}
memset(cor, -1, sizeof cor);
for(int i = 1; i <= n; i++)
{
if(cor[i] == -1)
{
qtd ++;
cor[i] = 0;
dfs_color(i);
}
}
cout<<(nope ? 0 : pot[qtd])<<"\n";
}
