#include <bits/stdc++.h>
using namespace std;
// #define int long long
const long long modulo = 1e9+7;
const int LIMIT = 1e9;
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int N;
cin >> N;
vector<pair<int,int>> ships(N);
for(auto&[a,b]:ships)cin>>a>>b;
vector<vector<pair<int,int>>> adj(N);
sort(ships.begin(), ships.end());
set<pair<int,int>> active;
for(int i=0;i<N;i++) {
auto [a,b] = ships[i];
while(!active.empty() and active.begin()->first<a)active.erase(active.begin());
auto final = active.emplace(b,i).first;
if(final==active.begin())continue;
--final;
while(active.begin()!=final) {
adj[active.begin()->second].emplace_back(final->second,0);
adj[final->second].emplace_back(active.begin()->second,0);
active.erase(active.begin());
}
adj[final->second].emplace_back(i,1);
adj[i].emplace_back(final->second,1);
}
long long ans = 1;
vector visited(N,-1);
bool works = true;
function<void(int,int)> dfs = [&](int x,int colour) {
if(visited[x]!=-1) {
if(visited[x]!=colour)works=false;
return;
}
visited[x]=colour;
for(auto&[v,wt]:adj[x])dfs(v,colour^wt);
};
for(int i=0;i<N;i++)if(visited[i]==-1){
ans<<=1;
ans%=modulo;
dfs(i,0);
}
if(!works)ans=0;
cout << ans << '\n';
}
