// n <= 2000
#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9+7;
const int mn = 1e6+7;
int n, kt;
vector<pair<int,int>> t;
vector<int> G[mn*2];
int odw[mn*2];
bool dwu = 1;
bool krawedz(pair<int,int> a, pair<int,int> b){
return (a.first < b.first && b.first < a.second) ^ (a.first < b.second && b.second < a.second);
}
void dfs(int v){
odw[v] = kt;
if ((v < n && odw[v+n] == kt) || (v >= n && odw[v-n] == kt)) dwu = 0;
for (auto i : G[v]){
if (!odw[i]) dfs(i);
}
}
int main(){
ios_base::sync_with_stdio(0); cout.tie(0); cout.tie(0);
cin>>n;
for (int i = 0; i < n; i++){
int a,b;
cin>>a>>b;
t.push_back({a,b});
}
for (int i = 0; i < n; i++){
for (int j = i+1; j < n; j++){
if (krawedz(t[i], t[j])){
G[i].push_back(j+n);
G[j+n].push_back(i);
G[i+n].push_back(j);
G[j].push_back(i+n);
// cout<<i<<" "<<j<<"\n";
}
}
}
for (int i = 0; i < n; i++){
if (!odw[i] && !odw[i+n]){
kt++;
dfs(i);
}
}
int w = 1;
if (!dwu) w = 0;
for (int i = 0; i < kt; i++) w = (w*2)%mod;
cout<<w<<"\n";
}
